Well, I took your advice JohnnyD and took things real slow...so slow as a matter of fact that I've only been able to work on the trailer twice since my last post! Did a lot of thinking and puzzling tho.

My business during the summer takes up a lot of energy and time. But I did manage to corrall No. 1 and No. 3 Sons' help at the end of July to get the second side cut and drill holes in the trailer. Gotta agree with No. 1 Son, the jig saw is not my friend. My next build

I'm going to have to find a better way to cut curves. There'll also be a little work getting the doors to have nice straight edges.
Floor has Herculiner on the bottom and front.
Cut most of the spars yesterday. Had to make a trip to Menard's as I cut a couple of them too short...getting used to the compound miter saw, you know. (BTW, saw some lovely green/blue/grey 6x6 porcelain tiles there on deep discount, so I'm rethinking the galley counter top. Somebody please talk me out of that).
Cut the 3/8" jog out of the back for the galley hatch. For sure, the jig saw and I aren't friends!

The plans say to use that piece to make the hatch ribs. Well, mine came off in pieces. Belt sanded things smooth and will use kraft paper to trace the edge to use as a pattern.
I find that in order to do each next step, I need to think 5 steps ahead. (That's what I get for deviating from the plans.) For example, before I attach the walls to the floor/storage base, I need to not only CPES, but apply some coats of spar urethane. In order to determine the height and depth of the galley counter, I need to build the slide-out tray for the Camp Chef oven. But first I have to practice using the Kreg jig. Think I'll build a bird feeder.
Still pondering the gas line from tongue to galley...that's connected to the height/location of above oven. So...gotta build the slide out tray. Step at a time.
I'm hoping to get it so that I don't have both sides of the garage taken up with the build when the cold weather comes. Husband is a rural mail carrier and I know he's not down with parking his car outside here in Minnesota all winter long.
Step at a time. Just gonna keep plugging away.