think the GS runs a 305mm disc and the RS 320MM so probably not,Steptoe would know,got a set off an RT.... Sorry just realised you were asking about 1100rs,no they wouldnt and neither would the ones i have
you can get a quick (and more sensible answer) if you ring Motorworks.. they should know. Or wait for Steptoe to see this question as no doubt he will at some point. I would make a guess at 'yes' but wuould ring Motoworks to confirm or deny that. I would assume that they used existing/remaining stock of the Brembos from the 1100 on the earliest 1150s. (seems sensible to me)