There needs to be an adaptor plate made for the three holes in the 185 case, stator plates I think are the same outside diameter with the top hole in the same position BTDC (so only two holes need countersinking in the plate and one threaded hole for the TM stator bottom hole), the rotor already fits and is in the same position as the 125.
I intend a really serious think about the whole process I'm doing (measure twice cut once etc) to make sure no mistakes creep in unexpectedly, I'm toying with the idea of bolting on a RM125S intake plate and manifold so I can run a 32mm carb so lots to think about but getting the frame done so I can at least start bolting stuff on is the first priority.