Nice trailer Jim, what tractor you pulling that with, and if you put on 16' logs, can you still raise those struts up? The only thing similar to my trailer is the bunks with short removable stakes, and planked over. The biggest differences is a stronger mobile home frame, A (A) frame hitch with a ring, and the best part of your trailer, is the tandem wheels which I bet helps it pull easier over stumps and bumps.
My trailer is from an 1/2 ton pickup frame with the rear axle welded to it. My hitch a 2x4, 6' long qu. stock with 1/4" wall, welded to center of trailer. It has one 2x2 sq. tube for a strut/stand, that sets in another 2-1/2 qu. tube 6" long with a removable pin like you have and same length as yours, but the 6" long piece is welded to pipe that fits over a smaller pipe, like in front of your strut, and another pin to hold the stand vertical or horizontal when hooked on tractor.
That way I can haul 16' logs and still swing my stand up horizontal.
Also if I haven't given you many numbers at once, I have a 2" qu. receiver welded in the bottom of my winch, so I can take the trailer hitch out when not in use, and I better get some pics. of that, or I'll be typing another 100 words, not the standed trailer hitch with ball.