1970 z/28 purchased at yenko chevrolet

[mmm70z]

hello, 1st time post. i am trying to find original sales or invoice from the purchase of 1970 z/28. an orginal protectoplate was with the car and i was able to find the original owner from the protectoplate and he verified that it was a real z/28 and he purchased it at yenko chevrolet. my problem is the trim tag does not say z/28.19 or 28.19 0n it. the protectoplate vin, the vin on windshield, and the vin on the trans are all the same. the eng., trans., and the heads are coded and dated consistently for correctness. need to be definitive about originality. what better place than the yenko web site! please help solve the trim tag mystery,any help or direction will be greatly appreciated. the vin# is 124870N552942. thank you, martin.