I tried a variety of methods before finally hitting on one that worked.

Went to Home Depot, bought a 10 foot length of 1.5 inch pipe and a sort of U-shaped cup (has a base and 4 screw holes around the flange. Think a half tube with a flange.

Drilled four pilot holes in the trailer frame, screwed in the "cup" ... cut the pipe to around 32 inches ... creased it slightly along the seam (Hand sledge and metal spike/chisel) so it would fold a bit and fit into the cup ... and after reading this thread, drilled two holes about half way up for a U-shaped thingee I had lying around .... Used an old dockline to stablize it sideways and forward (it was plenty stiff, but I figured, why not?) and bingo.

I'll use the tubing for something else I'm sure ($15), the cup (around $4) came with big sheet metal screws. Total cost with NY tax $22.22.

Every bit as good as anything else I've seen ...

Happy to e-mail an image if you want

gary