Building a trailer from scratch?

[RC Tractor Guy]

I have been toying with the idea of build a low loader trailer for my excavator from scratch, the reason I'm considering doing this is that to buy a tractor low loader is very expensive. I order a few wheels from SIKU when I was getting a motor and gearbox for my fendt so that should be okay. I was thinking of making the rest of the trailer out of copper the simple reason being I have an abundance of it in the shed from an old water tank. My plan is to make paper cut outs of the parts, cut them out and solder them together. I also want to hide a battery in the trailer and have control of the ramp so I can lift it up or down with a servo. I know it will most likely look terrible but I figure it will be worth a shot and if it does look terrible I can just go ahead and buy the proper one when I have some spare denarios.

Anyone else ever tried to make a trailer or modify an exsisting trailer, I've read of guys who have modified silage trailers before so there must be a few of you out there with some advice