TS frame is way lighter so if using that the Top rear engine mount could be sorted with a bit of ingenuity Brent as the TM engine is thinner and usually a tab gets welded to suit . "Perhaps" a length of pipe could be used as a long spacer with the TS long mounting bolt.
Not sure how a 185 would go in a TM frame.
I would score a TS185A as it has better porting to start with and the better clutch and use two separate ported barrels and ignitions.
My post was a bit light on detail, I actually have a bit more than 80% of a TM125, that's my starting point. I've got the TM125 motor plus I've got a 185 motor lined up so it's going to be a bit of a mix and match special.
I built one in the 70's and I seem to remember the top rear mounts match, the bottom right, rear mount is 30mm wider on the 185 and three out of four front mounting bolts line up. I'll make a second set of mounting plates to suit and a 30mm spacer for the lower rear.