The one that I found was difficult also and took a lot of Bondo. I ended up making a nasty resin copy from it but I ,may try to print it out again.

But the chassis was fun to design.

I the 3/32 x 1/2 stainless rivets for the front axles and I just couldn't resist putting a faux engine and exhaust in the back. If you're good at removing supports and have a lot of patience, I could send you a chassis file to play with.