OS2,
I have a Lancer 25 that I converted a powerboat trailer to fit. It was a very quick refit because I had to buy a trailer, find/build parts, refit the trailer and deliver it to have the boat loaded in less than two weeks. I had no experience in building trailers; no sailing or boating experience and didn't have a clue where to find trailer. Oh, and it was November. I did it. The trailer has worked for two years now. Parts are rusty and need painting. Here's how I did it.
The trailer had roller trees mounted low. I removed them and their mounting angles and bought some arms from a steel storage rack from work.
I bolted the trees to the posts after cutting them down.
They straddle the cross members and are clamped on with 4 bolts and plates on the base of each.
I built a roller bed to accept the keel.
I'll show you some pictures if you promise not to laugh. But remember, I know it's rusty. And you'll note by the narratives that I was grabbing anything I had to get the job done. This year I'm replacing all the parts that say "poor cousin". I've got fresh bottom paint on. I'm painting the sides. It's gonna look wick'd shahhp Earl! Anyway, this is for ideas. Good luck with your project.
Don,
Biddeford, ME