I built the 1/96th Cutty in about '60 or '61, and the jibboom broke where it connects to the bowsprit. I didn't have any little bitty drills, so I cut straight pin to about 1/2" long. I used a candle to get it red-hot, and shoved it into the head of the bowsprit. Then I repeated the process for the buttend of the jibboom. The two pieces never did match up perfectly, but I won a blue ribbon at the NM state fair with it, and it sat around my folks' house for 35 years. Mom finally threw it away without asking me if I wanted it. That joint never did fail as far as I know.
If I were doing the same operation today, I'd probably rebate the butt of the jibboom and drill the head of the bowsprit to take maybe .030 or .040 of the rebated portion. That would only be a few scale inches.
As far as using wood, I've turned some hickory dowell down to .022 (measured by a pretty fair caliper) and it's a heck of a lot stronger than an equal bit of plastic.
Turning styrene into fantasies for 50 years!