Soft back jimny conversion?

Hi, new to this forum so hope I’ve posted on the right page! Apologies if not.
I’m an agriculture worker so my jimny gets used mostly for that sort of work - very muddy fields, horrible tracks rutted by tractors and the like. I have a soft top and was wondering if anybody on the forum has tried building a back out of marine plywood or sheet metal, similar to the covered truck backs used on pickups and utvs?
cheers, any thoughts would be welcome!

Several people on here have 'tray-back' and flat bed, I am sure one of them will post some pictures.

A company called Yomper make them, see below

www.yomper4x4.co.uk/gallery

Probably the Field Star is close to what you want?

Yomper start with a donor car and then do a lot of work to it, you basically end up with a new vehicle.

www.kapmotorsports.co.uk/
Rhino rays
dependent on where you live 
Kap are Leeds
Ray is Brighton

Or even Keith Phillips has converted a few now
Leeds
jimny4k.com/forum/viewtopic.php?t=8

Thanks guys, have looked at the conversions before and although one would be ideal they’re a bit far out of my budget. Was more thinking along the lines of the carbon fiber hard tops kits I’ve seen around, but seem to also be crazily expensive. I saw a Facebook post years ago for a rough top made of checker plate, but can’t remember much about it!

I have seen a ibc tank used has a hard back cover