HD Pickup cab thingy that I saw..

["Jason and Maria Colavecchia" <jasoncolavecchia@domain.elided>]

I had the privilidge to spot and talk to the owner of a '74 or '75 pickup. 
It had no body on the back, but was a dually with a BIG spring pack with a
set of helpers on it.  It was a 392 with a wide box 4 spd (not sure if it's
t18 or t19) and TOWING gears in the diff.  It's IFS front suspension, with
beefy-looking coil springs (like, bigger than normal..)  The fella who
owned it wasn't sure of the model or exactly the year, as he inherited it
from his dad, who had bought it new.  It was first used as a sign truck,
and only had 10,000 miles on it when this fella got the truck.  He had it
converted to propane and had a cube van body installed to move around
printing supplies. He said it was rated for something like 10,000lbs GVW. 
It was finally parked and the body and propane parts stripped off.  There
it has sat for one year...

My question to the digest is this:  What Model, and is 10,000 gvw
accurate???

Jason and Maria Colavecchia
1979 IH Scout II,  V304, modifications ongoing
1969 IH 1210D Travelall 3/4 ton, V345,  restoring slowly