Re:
I can do you a pair for a fiver posted.
Domt know if they are the same height as fox, but if you know I can confirm. Main difference visually is the fox omes are slotted, rs ones solid. You could cut slots in I suppose.
To size them I used very fine sandpaper and slowly worked them, checking very frequently so as not to go too far. This I've only had to do once, they fitted perfectly all other times. I did this without the seals and foam rings fitted, and had the lowers inverted to keep as much of the results out of the lowers as possible. Cleaned the lowers before fitting/rebuilding.