Someone on this forum once offered to reproduce the Lithgowicon mounts, both high and low. The costs were so high that for spare sets "in whatever case" I passed. Maybe search can help you.

Regarding the PPCo base, I might throw in that there are different patterns of the bases (from what I've learnt from Roger). So if you come across one that doesn't look like one pictured above it doesn't necessarily mean it is a reproduction.