Sennheiser HD 598 replacement pads?

I had a whole post written out, then accidentally pulled down and refreshed away the whole thing....

Long story short, I want to get my GF replacement pads for her old 598s. I'd like to get OEM if possible, or if there's anything that's actually better or actually comparable.

(598 is so light, comfortable, transparent, durable, and actually sounds decent)

I'm thinking about getting OEM 599 pads direct from Sennheiser.

Does anybody have any experience with putting 599 ear pads on the original 598? Any other suggestions? Ideas? Wisdom? Anything better?