Hi Matt, Welcome from a fellow "Brit"! thumbs_up
Is that a Rover lump hiding in the back of your rail. I'll bet she goes well! grin
Back to the main subject....It's your truck,do it the way YOU want. To fit all the bodywork on a later chassis is do-able but a lot of work.
The other option is to upgrade what you've got i.e Brakes/steering etc. There are plenty of vendors in the links section who could point you in the right direction.
It's all down to how much £££££'s you want to spend.
Nice truck anyway!
Jock thumbs_up

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.