Bob–we’ll see what Stevie’s answer is, but I used 3/8″ roundover on the butt block. the book says 1/2″, but a 3/8 roundover plus 3/8 fillet nicely fit with the 3/4″ thickness of the butt block. as for a bit, my 3/8 roundover bit assembly with bearing is too long and bottoms out on the top of the underside preventing the bit from coming in contact with the butt block. so, harbor freight to the rescue. they sell a CHEAP (meaning quality) set of bits that includes a 3/8 roundover with a guide post on the bottom that is short enough so it doesn’t bottom out. the downside is that for 7.99 the set is high speed steel, not carbide tipped, so you end up burning as well as shaping the wood. I’ll dress it up a bit with the sander but of course it won’t show.
on the sides, I can use my carbide-tipped 3/8 roundover with bearing. but as for the front and rear, since the panels angle out from the bottom, the bearing will keep the bit too far away from the edge to get a full 3/8. I’ll have to finish the roundover with the sander. I dare not try to freehand using a bit without a bearing.
good luck getting your camper ready for the ARRL event!
ken