Short dumper box?

[TheBennyB]

I just came into possession of a tamiya chassis that was shortened and a bruder Mack cab put on. It's just a single axle now in the rear so was thinking this would be a prime candidate for making a dumper for the kids to mess with. I've done a bit of looking around and can only find 40-45cm boxes and I'm looking for more of a 15-20cm length. Was just wondering if anyone was making/selling anything in this ballpark before I get into fabricating one as time in the shop is limited these days. Thanks for any input.