I have done this repair. I used teak from Buck Woodcraft, Inc. They offered small sizes which I needed. The old teak is glued in and I chiseled and ground it out and then built it up with epoxy and filler. But first I cut the needed plug out of the new teak and placed it over the old teak and carefully penciled a line around what needed to be cut out. I then used a Dremel tool to cut along the pencil lines. Go Slow! If you do it right the new plug has to fit.
I then worked on getting the stains right so the new teak would match the old. I epoxied it in and replaced the window with 101. I like that you can clean it up with alcohol.
Try http//www.buckwoodcraft.com/teak_veneer or some variation of that.
I have pictures somewhere. If I can find them I will post them.
Larry Lee
Annabel Lee
E-32-200
Savannah, GA