Geoff, the diff between the CMS frame & the 73GP bike, apart from the FMS rear end, is in the construction of the rear subframe. The seat rails on the CMS sub-frame are flat & continue on to the rear loop (where there is an upward kink behind the top shock mounts), w the rear upright tubes butting up against them.
So can anyone spot those differences in any close ups of Jims GP bike?
Not sure what you mean Geoff, but the diffs I'm describing can be easily seen even from a reasonable distance.
Another bit of info - the Schwerma pursang frames were quoted as 23.5lbs incl s'arm.
Jerry, wrt carbs, as far as I can see (in pics) the sponsored bul riders of the era (73) at national level in USA seem to be still using Amal carbs, tho Pomeroy could have used a bing. In the article on his late 74 big-bore (in Dec DB) it uses a Bing & Pomeroy is quoted as saying he prefers the bing to the std Amal
