Sorry to necro this thread once again, but I have owned a pair of Sony MDR-F1 for many years (since they were released back in late 90's). I still use them from time to time and over the years the Escaine Earpads and the Escaine headband material has worn (and torn) slightly.
 
I checked Sony and they no longer sell parts for this model. I checked online and there are no 3rd party replacements parts for this model. I could drop 400-500 on ebay and buy a new-used pair, but I would prefer to just fix the ones I own.
 
Being that there seems to be no direct replacement parts, I am not faced with having to mod these myself and fashion a new set of pads and headband.
 
I was considering buying another brand's pads and headband and try to mod it to fit my model. Does anyone know of any brands that will even fit this unique ear pads size and shape?
 
If not I likely will have to buy fabric and foam and try my hand at crafting my own set. Sourcing Esaine is very difficult on its own, but I think I can use ultrasuede in its place.
 
Does anyone here have any links or advice on where I can go to gain the knowledge for this so I can do my homework before I get started? 
 
Thanks in advance for any and all help!

Beyerdynamic's DT990, 880, 770 pads fit well. You will have to make your own headband.

thanks a lot for this tip, I was hoping I could harvest another brands pads and make them work for these.

I thought I would come back to this thread and share restoration success. I bought the Beyerdynamic's DT990 ear pads for my MDR F1's. 
 
They were exactly 100mm and fit the outer earpad rings perfectly. The interior cuff that wrapped around however was way to short, I did managed to make it work in the end though. I decided to go with a black pads even though the stock color is a silver/gray color on these sony's. I just was never going to be able to color match these pads to the original color. I decided black will still look good if I make headband black too.
 
My original headband was shredded and old. This was gonna be the hardest repair. The interior plastic was cracked too. I had to find a plastic that was same consistency and flexibility. I cut it to shape and filled in the parts that were broken. I purchased some black "ultra suede" which is very similar to the original Escaine material Sony used! It did require me to brush up on my sewing machine skills to make a tapered ultra suede sleeve. After a couple hours of sewing and plastic cutting I got everything finished. The headband came out near factory perfect, I surprised myself considering this was my 1st try ever doing something like this. I used a hot iron to iron out the fabric on the headband to get it flat and smooth along the body length, then reattached it to the headphones.
 
Here is the final result... new ear pads and new custom head band.
 
I uploaded the pictures to imgur
 
http://imgur.com/a/HbSNj
 
Thanks for the Beyerdynamic tip, it saved me a ton of time trying to hand craft my own. 

I'm glad to see that there's still people that come to this very old thread to check out the predecessor of my favorite daily headphones, MDR MA900. Now that Sony has updated their flagship closed line (from Z7) with the MDR-Z1R when will they update both the MDR F1-MA900 and MDR 1R - 1A line I wonder?
@Maximum3D and anyone else sourcing for replacement pads I'd say, won't MA900's will fit the bill just as well? As the driver size difference is moot as its hanged by the gap, I'd say it better for people trying to keep it as close as original, as Beyer pads is a bit thicker, and has smaller hole.

well i think they were recreated by FOCAL in Utopia, the full open type sound

I am the owner of a (now) broken Sony CD 900 ST, and I always found it very special, always very hard on recordings, showing the best when it's spot on, and showing the worst when the recording is not so great. Then Sony released an interview with the team who released the new version of it (even they deny to call it like this) the Sony MDR 1ST. And by searching the chief engineer background, Koji Nageno, I figure out about the Sony R10, the Sony F1. I was very surprised by this F1. Not that the R10 should not be mentioned, but being a product designer myself I see in the MDR F1 everything I like about a product. It is ambitious, it is uncommon, and seems to have a very underground fan base which I am happy to just joined. Using magnesium as the construction is an expensive process, compare to using plastic, or even stainless steel and so on. The fabric is well preserved on this sample but I may try to update it myself. But keeping the grey finish will be a tough one. Let's see. I would like to keep the original design intent and avoiding tweaking it, as I did not bought this unit for the sound. I need to mention that I am listening on them from a Grace Design M900, and I also own an amp for the CD 900 ST but did not try yet, as this amp is specific to the 900ST.
I approach this unit more like an interesting piece of technology. I very much enjoy the openness of the device after being struck myself trying the AKG1000, but which I found harsh to listen, and to expensive for what it was. I purchase this online from a previous japanese owner. But one thing really surprised me was the impact of the sounds. Not flat or any lake of bass. Some hear will might say that the Sony CD 900ST maybe is the reason behing my impressions but using also a Koss Porta Pro I can tell what is bass oriented or what is not. And i found this MDR F1 very well tuned. Definitely not best in class regarding details and clarity compare the the Sony CD 900 ST, but very pleasant to listen. I tried electronic music such as Para One - Epiphany, Jazz such as Dave Brubeck - Take Five, classic such as the Requiem of mozart from John Eliot Gardiner, or Radiohead - In Rainbows, and did not find a flat sounding, harsh sound that sometimes rock music can reveal on low bass oriented headphones. Maybe Converge - Jane Doe sound a little flat, the impact was not as intended from the band, but it was still fine. Switching back to Vince Guaraldi - Jazz Impressions and i was surrounded by warmth and steam.
I have to say that changing foam might change a slight the speaker distance and this will maybe impact dramatically the sound. I think sound positioning on the ears, and foam thickness is a key point in these headphones. But I found the same for the Koss Porta Pro, by increasing the foam pads I reduced the bass impact and created a more balance device.
So thanks for the reviews I read about those, I am a happy new owner, and might keep digging into this glory of adventurous and courageous headphones maker, from Sony or others : )