Early A body Car

I am currently eyeing two barracuda cars. They are for sale within a four hour drive from my house. One is a 65 V8 auto and the other is a 66 Formula S which is $2500 higher than the 1965. The 65 is 100% done and is hunter green with a black interior. The Formula S is a copper color with a black stripe and has some rips in the front bucket seats, but comes with new upholstery and the interior is also black. It is a V8 automatic. I know how to do the upholstery myself since I did this to my 64 Dart GT. The 65 is absolutely perfect. I believe the Formula S would be more valuable since it claims to be a matching number car. I need to know how to check the serial numbers on a V8 car. Any tips would be helpful.