John,
I'm moderator/owner of the RepowerAndRegear list on groups.io
We have had several list members who have done extensive repairs/rebuilding on Shays, mostly PFM.
One of our moderators in Lakewood is a long time repair person for Caboose.
Phil Floyd, 'The Shay Fixer" is also a long time member, both have made numerous posts about getting Shay models running.
I also have a Repowering Guide web page devoted to PFM Class B Shays at www.shastasprings.com showing how I've repowered
dozens of PFM geared locos, SG and NG
I would suggest joining the list and searching our archives on the subject of 'Shays'.
Contact me at
ken@shastasprings.com for an invitation if you want to join.
ken clark
www.shastasprings.com