Help... Vin #'s dont match

There is no door sticker, No fender tag, The stamped numbers on core support are not evenly spaced and are somewhat crooked... I am a machinist so it could be me just being anal... The car was advertised as a numbers matching car...
Owners wife wasn't an "old lady", late 50,s early 60's maybe. (what one considers old changes over time)....
They were under the impression the car was original when they bought it....
They gave me receipts from shops, so Im assuming the owner didn't work on it himself.... (he paid for brake jobs, carb tuning, and a lug nut stud to be replaced) Someone who pays for work like that isn't checking numbers on a car....
So its my fault I didn't check for vin numbers on the bottom of the block.. I saw the FW340xxxxx on the front pad and I figured 340 car, motor is a 340, lady seems honest enough, I like the car, and if I don't buy it now, it will be gone tomorrow.. So I bought it...... Shame on me.....

As I go over the car, I realize it not a numbers matching car... Fine Its a 340 car with a 1970 340 in it....

I don't know Mopars so I do some reading..... I read about vin stamping, I look....
Vin on dash and core support match but package tray doesn't. I freak out...
I post my dilemma on here and open a can of worms I probably shouldn't have... But whats done is done....


I spoke with the guy that I guess you can say built the car back in the 80's and he assured me that nothing is stolen on the car and he has the paper work to prove it....

So at this point Im waiting till the weekend when I have time to drive out there and take a look at what he has for it, before I do anything further.....

Im not looking to get anyone in trouble or have any trouble for myself.

I play with these old cars for fun, I asked on here for advise on what to do and I guess I got it....

So for now thanx guys....

Just FYI, before I do anything further with this car, It will be undoubtedly and legally registered by the State.....