My take on that particular component whether two-piece or a single was the fact that the mounting base was positively crude what with big holes on small studs to slop the thing into adjustment....a rather marginal attachment: dependent on the friction provided by three small studs.
I chose to mount my plate solidly to the case wall with three precision larger bolts that fit the 180 degree layout exactly as both the mount and case were machined exactly true to the point of the spindle mount being nearly a light press fit.... it other words it wold not move
from position with the nuts loose. The idler shaft was hardened and ground tool steel to the large idler's roller bearing specification. And, most importantly, the thicker than stock tempered high grade alloy "steay plate"was bored to the exact position of the spindle end mounting once correct ROUND cam gear mesh was established allowing no cantilever movement in yet another oversize adjustment hole. By the way, how many of you folks have ever chucked your stock large gear mount into a lathe.... and used a dial indicator to establish
if your spindle was a true 90 degrees from the mount? you may be surprised at how many large idlers are running crooked and given their large radius.... a true mesh means a lot to a gear. But, easy fix here.... as long as you have the spindle chucked up a light face cut
across the bottom of the base will square it up as it should be. Of course someone is going to ask how I achieved cam gear mesh with a solid idler boss..... well, that's a whole 'nother story into the land of total overkill.