Great work! If you ever find another '68 here's a challenge for you. This is my friends '68 Hurst/Olds. He's been the second owner since 1983. Only 515 built.
Here's an option if he gets them back in stock. Back in the 90's there was a company that cast some high quality Alcoa dually wheels. I had a couple sets I had chrome plated for my trucks.
https://scenesunltd.com/products/s52-1-25-19-5-dually-wheel-set?variant=49624255892
This may be a little bigger than what you're looking for, but AITM makes a 10' Garwood bed.
http://aitruckmodels.com/product/garwood-10ft-dump-body-kit/
Sorry for the delayed response, I haven't been on the site in a while. The cab and bed are from AMT's C-3500 phantom dually kit. I had lowered the original kit and made bigger rear tubs to fit the tires.
I ordered quite a few parts this Spring prior to seeing the 2015 health issue posts. I received all of my parts I believe within 4-5 weeks. Maybe they received so many orders they are trying to catch up similar to the Modelhaus?