That is looking sweet!....
I owned a 56 Chevy 3200 series years ago..(1978 to be exact--had it a couple of years)..I kick myself in the a$$ for selling it(especially when I see one like your at a show,or online!
)..it wasn't rotted all that badly.just had some floor rot..being an 18 year old goober,I patched it using an old snow shovel and my friends fathers ancient arc welder..
It looked horrible(the floor!),but at least it coverd up the holes..man,what I could have done with that truck if they had MIG welders then--I had several 71-72 GM trucks too,a couple of K5's(one was a CST!)and a 71 GMC K1500..all were rusted pretty bad,but not to the point they were not fixable..I could have put one of their chassis under my 56,much like your doing!..
...dont see many of those here anymore.. 
I owned a 56 Chevy 3200 series years ago..(1978 to be exact--had it a couple of years)..I kick myself in the a$$ for selling it(especially when I see one like your at a show,or online!
)..it wasn't rotted all that badly.just had some floor rot..being an 18 year old goober,I patched it using an old snow shovel and my friends fathers ancient arc welder..It looked horrible(the floor!),but at least it coverd up the holes..man,what I could have done with that truck if they had MIG welders then--I had several 71-72 GM trucks too,a couple of K5's(one was a CST!)and a 71 GMC K1500..all were rusted pretty bad,but not to the point they were not fixable..I could have put one of their chassis under my 56,much like your doing!..
...dont see many of those here anymore.. 
It's a '87.

. Oh, well. We could probably talk all night could ofs and should ofs, and didn'ts.