I have one in my hand my part# HTD575-5M.
I also have a Grubee 4G with the same 20T/100T belt and part #5M57.
Maybe one of them will match better.
I haven't had any breaking issues with them, the trick is not get the belt too tight.
The 7G's primary is the clutch bell riding on a busing on the shaft not a bearing in the case, get it too tight and that bushing will stress and maybe even wobble, best check your before you order a belt and see if you need that too.
I'm in Sunnyslope and will be getting some of those belts when my new production run parts for the 10G KCK Long Shaft parts from Don get here.
In short the 10G jackshafts itself to the right hand pedal side to be tied into the pedal system with the Sick Bike Parts bottom bracket freewheel system.
I am still developing an all new motor base that will completely eliminate any motor or base moving once in, and no manual chain adjustments but that's easy, like a direct there this is one more chain, but it is short and perfectly aligned down to the pedals ;-}
Anyway that is pessimistically weeks away, and before you ask, no, it is not a bolt on replacement for the 7G which has a long shaft HS 142 engine to accommodate the clutch bell Primary on the engine shaft and no clutch on it.
This is for the other HS 142 engine with the clutch attached and short shaft as the 10G's clutch bell and Primary are part of the transfer case riding on bearings.
Just FYI, hope it helps fellow Zonie ;-}