Front end removal/installation advice

[HIGHWAY BY THE SEA]

I have bought all of the necessary original GM parts to rebuild the front end of my 67 GMC 1 ton, and I have a question. I was going to remove the existing rusted/dented front end with my chain hoist, then remove the wheel wells from that assembly.
Using these removed wheel wells, I was going to build the new front end with the 67 fenders, the 68 Chevrolet hood, and the 72 GMC radiator core support by assembling them together off of the truck.
Then I was going to attach the new front end to my chain hoist, raise, then lower it onto my 67, then attach it.
But the parts seller warned me that it is very hard to do it this way and make it fit right. He suggested that I build the new front end onto the truck one piece at a time so that the parts fit better.
Any thoughts from the experts?