VIN tag # vs title # question

[WIDESIDE72]

I looked at a 72 c10 for sale today, and ran across something i have never seen before. The seller said he bought a rusty swb stepside for the swb chassis. The story is he scrapped the cab on it and installed the cab from a lwb truck onto this chassis. The VIN tag started off "CE142..." But the title read "CE132...". All of the subsequent numbers (unique sequence numbers) match. Has anyone ever seen this? Should i be concerned? Should I ask the seller to get a corrected title? He said he didnt have the title to the
Swb truck. It has a different number stamped on the frame by the steering box. The engine is out of yet another truck with a unique number. ???