I got them direct from AKG in the US. If you're in the US, contact Frank Rodriguez.
or call him at 818-920-3279. Great guy, very helpful. I paid $14.74 per pad, $7 FedEx Ground.
If you're not in the US, you can get them from Moon Audio
available in grey or black ($7.50 extra per pad!) Not cheap. Other options are
lists as black, doesn't give the part number.
I thought I saw them at Full Compass, but don't now. YMMV.
The AKG part number is 2458M12020
Thanks a lot!