Re: Trailer rollers
I had a Catalina 13 and replaced the trailer rollers with out-door carpet pads on flat plywood (set at the correct angles / position for trailering). I felt more comfortable with the cushion they provide for tightening trailer straps.
So if it's a light sailboat, the soft carpeted pads are another option, seemed nicer on the outside of the boat than the friction of rollers.
Otherwise they usually sell rollers at some (but not all) U-Haul type places or some (but not all) auto-zones. Clear would be the best choice in rollers.
1985 Catalina 30 Std Rig "A Cenoura"