the 954 caliper pistons had a different coating than 929, for lower friction
I've heard that before, but not been able to confirm it. In any case:
Caliper pistons (all same physical shape):
01/2 RC51 (SP-1) and 98/9 'Blade = 34/32mm
929 = 34/30mm
03-> 'Blade and 03-> RC51 (SP-2) and many 600s = 32/30mm
929 (and 01/2 RC51) = 3/4" ~19mm
954 (and 03-> RC51) = 11/16" ~17.5mm
Apart from the 5/8" device on 98/99 'Blades, earlier bikes used a 14mm M/C with same lever as 98/99 but which has a different lever ratio (mechanical advantage) to later bikes and provides greater hydraulic pressure. I have used a traditional 14mm M/C with the 34/32mm calipers on SP-1s, FireBlades and Valkyrie and can confirm that it works superbly. The other calipers with smaller piston sizes will work, but ultimately would not be as powerful.
CBR1000RRs all use a radial master cylinder which IIRC is also 11/16", but the radial design provides greater mechanical advantage than any previous M/Cyl design, hence the reason for using them. I've not tried with a 34/32 or 34/30 caliper, but it might be a bit soft. Probably not, hhmmmm.
BTW, the advantage of radial calipers is to allow different disc sizes to be easily used. Don't be fooled by technobabble about stiffer mounting etc. They do not provide any better braking - unless you make use of their stated advantage and fit larger disks
I guess most of you didn't need to know all that