Dunno about those forks specifically, but I've always used Castrol motorbike fork oil - just go into a motorbike shop and get the lightest oil - weight of 7.5 or so - it's ideal and much cheaper than mtb oil - and it's the same thing!
Hmm thats what I was thinking of , on the instruction book for RS-1 it says transmission fluid , so I think I will need a 7.5/8 w
thanks for your input , always full of help as ever chaps