Just a comment on the ones you've already seen -- planetman's suggestion seems to be the most likely--that is--the oil is draining back into the sump--explaining why there isn't much in the filter. As suggested - many oil containers now supply you with 5 qts so there's the possibility of not realizing you've added one too many.
A '72 dipstick should just drop into a hole in the block and it is formed by a single rod doubled over to make the "handle" and to act as a "brake" so it fits tight. The B20F metric motor (1975--maybe '74 too) has a short tube extension in the block's dipstick hole and the dipstick has a spring steel handle that makes it stand taller in the engine bay. Maybe there's a mix of components? -- Dave