I haven't chimed in because, although I've investigated this for years and have gathered two sets of RC51/929 parts to do the swap on two of my bikes...
...I haven't actually done it.
Anyway, speaking of RC51 lower triples, one thing I've noodled about from time to time is the lock-stop issue. (The cast stops on the RC51 triple are incompatible with the VFR's frame, so people generally grind them off the RC51 triple and make new ones in the correct positions.) I've seen it done a few different ways, but not having access to a machine shop, I'm struggling to figure out an easy way to make new stops. But then I had this idea, see...
How about taking an end mill of an appropriate size, say 12.7mm, popping it in an everyday drill press and cutting straight down into precisely measured locations in the gull-arm's angled surface (which would be suitably anchored to the drill press). If I cut just enough to allow a circular spacer of appropriate length to sit perfectly vertically, secured with a socket cap screw threaded directly into the triple clamp, it should work great, right? (I hope so, because I added a 1/2" HSS end mill to my last McMaster-Carr order...)
Ciao,