Paul,
Thanks for sharing the pics with us. Most of these, if not all, off road crawlers and carriers for the logging & mining industries, use Sherman drive train parts fitted only to a newly fabricated hull. So all one gets when buying one of these conversions is actually only a set of bogies, final drive, idler wheels and track, which will be (very) worn by the nature of their application.
Also see my web page
"Shermans into ploughshares".
Regards,
Hanno