Just a brief comment on something I noted on my 73 and my wife's 74 Paramount P-15's.....

On both bikes, the triple crank set is the pre-1973 version with no date code. I can only guess that Schwinn ordered a whole bunch of these much earlier and did not use them very fast. The non drive cranks on both are marked for 1973, so no one was too concerned about the date codes.

I would prefer for my bikes to be as "correct" as possible, but I use later clincher rims that have hook beads as well as SunTour barcons. I am willing to make some modifications for functionality, with the bike overall as correct as I am able to make it at the time. They are usually all a work in progress-that's half the fun!