A while ago I found an alternative to the small rear exhaust mounts at the rear of the mini that always seem to break.
I managed to find a mount that is the same cotton reel style and same 20mm width but 40mm diameter rather than the minis 20mm diameter.
I've been using one of these as a gearshift mount(non A series engine) for some time and it's stood up better than the mini mounts.
Anyway here's a link, they should directly replace the standard items in the standard location.
https://www.enginemaster.com.au/mackay- ... aust-mountSearch Mackay EXM1066