Even if you did change so many parts and provided the drivers were in pristine condition, I wouldn't expect them to sound better than brand new HD580's!
If I were you, I would stack up euro upon euro and get the new ones. Let's not forget that the 580's were the top of the line Sennheiser cans some time ago...
I don't have the MS1 but since you say they are quite energetic, the Senns may not be your cup of tea. The HD5xx family - people say that the HD6xx too - share some common sonic features: delicate treble, sweet mids, nice but not exaggerated soundstage. There's a lot of discussion on this forum related to the Sennheiser sound.
Personally I think it is a relaxed presentation of music, focusing on the whole rather than on the minutest parts of it. Senns seem to be tuned for music-lovers who want to concentrate on music for long periods of time, and they try to reproduce the concert - hall acoustics. They are not studio headphones, therefore may not satisfy those who want to hear every imperfection of the master tape. Well, they sound a bit "distant" compared to the most detailed cans around. The only partial exception being the HD595 which I am currently using, and I can testify that its presentation is noticeably more upfront but with slightly narrower soundstage.
Listen to the 580's before buying, if possible, of course (yeah, I know the Fnac people who don't let you listen to the audio gear...as if they sold potatoes...try some small high-end distributors, you should find some in big cities. If not, beg, borrow or steal
).
I hope it helps.