I did the transom on my 2004 Lund Alaskan 1800 a couple winters ago. Im lucky to have a large enough shop and a beam/chainfall to help with removal and installation.
Heres the transom coming out..in one piece for a template. Can you believe how rotten it is?? Crap wood with no type of glassing or sealant
Heres new marine grade 3/4" ply ready for the template
2 pieces glued and screwed together with PL construction adhesive to get 1 1/2" width
Polyester resin 2 coats applied
Then glassed
lots of resin, ready to be trimmed
lots of 4200 for everything
transom in, waterproof sealant over the top 1/4, clamped to seal
Splash well reinstalled, everything that was out reprimed
sealed and painted
Motor reinstalled, 4200 used on every bolt, screw, rivet
The only blurp was I didnt calculate quite enough for the added thickness of my extra glass/resin job. It did fit snug, but will as others have said, out live/out last its owner.