Looks like an overall nice car. In Europe maybe the pictures would have sufficed but I've already learned in America people are used to more professional presentation.
P 1 - Wheelarch trim. Not something to expect on a Bavaria. The front ones are very delicate and often short-lived. Which means they are near unobtainable, at least east of the Atlantic.
P 4 - Rear panel painted. BMW stopped that about early summer 1972. Exact date? May depend on the colour, probably until the stocks were used up. Nice item in any case.
P 13 - Always like to see the tank lid with the curved horizontal trim part. Quite exotic except for America. Some Italian cars had it, too.
P 27 & 31 & previous posts - Front seats may come from an E3 Series 3 of 1973/74. Wide-post headrests and early rear sides. New seats similar to the E12 arrived about the beginning of 1975. The cut of the upholstery is all Series 3. no changes between 73/sep and 77/feb. Of course the seats do not fit. BMW modified the seat mounting consoles with the introduction of Series 3. Not easily interchangeable between Series 1 & 2 and Series 3.
P 28 - Series 2 cut upholstery, excellent condition. Correct short armrest.
P 32 - Angular door handles. Standard with electric windows (and on all LWB E3).
The more you look at it the nicer it gets. All the expensive parts seem in great shape: doorpanels, carpets, headliner, trim, the whole boot etc. Leaves only the front seats to address. And maybe a four-speed box for Christmas.