PM will be sent with link. Good luck on the purchase. These old POH's are kinda nice, simple and not like 8,000 pages. Sometimes you'll be wanting more info but pretty good.
There are lots of tables for MP/Prop settings but in the end (and ironically its in the POH) you will probably adjust the prop for the smoothest operation. If you are looking for things that will be costly or confusing here are some that come to mind for your pre-buy:
1.) Know exactly when the mags were last looked at. Its very common to have one at like 900hrs and never gone through
2.) Obviously look for a bent firewall from hard nose wheel strike or porpoising
3.) On some models (ours) the tail beacon is routed through a relay behind the radio master so you might have to turn on the radio to see that light work
4.) If the nose has wheel has been hit hard there is metal part just in front of the nose wheel, hard to describe, that can be cracked and very expensive to repair.
5.) On our model Cessna paid for the optional pilot seat floor belt which gets rid of that crappy pin. They won't pay for the labor but its an expensive part so queue that up with your A&P after the purchase. It is so much easier to move the seat back and forth with that belt. Unfortunately they won't pay for one for the passenger
6.) Not all seats are height adjustable which can be a PITA if you are short
7.) During our year (1972) there was not a passenger openable window option, hopefully by 1975 some from the Nixon/Ford/Carter era fixed that lame choice.
8.) It should have fuel bladders and can either be 60gal or 78gal. If it has a fuel stick don't just assume it for the corresponding tank.
9.). Both our pilot side and passenger side door handles and latches work well. Our co-pilot door steward is broken. But our door and baggage lock still work!
10.) See what kind of battery you have, ideally you will switch to a newer Concorde. When I switched to the newer Concorde the battery cover had to be modified. That modification went like this: Mechanic say "Buy the battery yourself and save $30, reshape the cover yourself another $50 and I'll inspect it." Me say "Ok!" It was easy
11.) The Conti 470 is probably gonna run really rich. After startup, especially in warm climates you can pull the mixture back right after starting and oil comes up. Many even start it partially leaned.
12.) You might notice it rumbling and popping a bit in the downwind with full carb heat (needed per POH). That carb heat just makes it run even richer.
13.) Lean aggressively during cruise or you will pay for it. During top end break in we ran full rich and were burning like 15gph or more.
14.) If he has time, check the tach. Ours is off a bit during cruise (reads fast) and ironically took quite while to figure out.
15.) They often leave the co-pilot headphone jacks on the center pillar...its a PITA and I will move it the next time we touch the audio panel.
16.) Check for windshield rattle at idle. Ours did and on the first annual the A&P re-sealed it and it got nice and quiet
17.) Make sure it has the correct, new NON-KILLER caps
18.) With a older battery starts, especially hot starts can be a bit of pain. With a new battery a hot start should just be turn of the key (took me many variations to get there because of the old Gill battery).
19.) Check the cowl flaps to make sure the move smooth and clean. Equally important, make sure they are still attached really good. Some get old and fall off and costs lots of money.
….then there is all the stuff and actual A&P will do
I hope it works out. Don't be afraid to walk or ask questions