RE: Reassembly procedure. OS Gemini 120 & 160
All of the bearings are still available.
OSMG3060 26731002 FRONT BEARING 40-240 US$19.99
OSMG3076 22130004 MID BEARING 120-240 US$20.99
OSMG3040 22631019 FRONT BEARING 12-300 US$17.99
OSMG3120 46030008 REAR BEARING 108-160 US$24.99
OSMG3216 46031005 CAMSFT BRNG F 120-300 US$17.99
You'll need one of each, but two of the camshaft bearings (the last item in the list).
These parts can be ordered through any hobby retailer who sells Great Planes kits and accessories.