Lots of neat stuff in those pics... a race fans delight!
These are just some of the things I noticed:
the '70 b body next to the '71, taken in '72
'72 Super Speedway cars, #11 & 43, with ultra smooth bodywork and carefully fitted bumpers. These cars were among the first to take advantage of some tricked out bodywork to cut through the air. Note the still-seperate door skins - Nascar did not yet allow one piece/molded side panels.
the Hemi just sitting on the floor.
the 43 car with the black circular padding behind the driver's seat is still around today - the padding is over a circle with a peace logo in the center, a builder's trademark.
the Superbird under the cover in the parking lot - I'm not sure if the rules still allowed a Superbird in '72.
the '71/'72 Plymouth under a cover in the parking lot - '72 was the last year Petty ran both Plymouths and Dodges.
Richard himself working on the cars and in the shop - you won't see any modern day drivers doing that!
a VW Beetle in the parking lot

though all the cars in the pics were Hemi cars, '72 was the first year they started using 340 engines (supposedly all the Hemi cars used painted rims, while the 340 ones had chrome rims)
These are really neat pictures of the way teams used to operate. Petty at the time was THE team, with the best of everything. Can you imagine a top team today letting their cars travel on a trailer behind a truck, with only a cover for protection?