Using parts from a later model can get problematic. Somewhere in the FARs there is (or was) a requirement that only parts specified in the manufacturer's parts catalog for that serial number or airplane could be installed, or their equivalent such as a PMA'd part, or under an STC. The parts catalog will have listings of various seat part numbers that are eligible for installation on certain serial number ranges; this constitutes part of the "Type Design" that has to be maintained. Bell206 would have the reliable opinion on this. In Canada we have this rule:
Besides that, finding a serviceable used infinitely-adjustable Cessna seat will be difficult. And expensive, since everyone else wants them or wants parts off them. Parts for these seats are horrifically expensive.
These things are getting old (the 172M dates to 1974-'76 or so, 50 years ago) and they have structural weaknesses such as cracking seat bottom frame legs, wallowed-out roll pin holes, worn seat-back adjustment cams, and worn clevis pins that run on those cams I've found those pins worn more than halfway through; if one failed on takeoff, the other, now bearing the entire load, could fail and the seat back flops back. The pilot instinctively pulls himself forward using the controls, and the resulting stall and crash can be fatal. All because mechanics never looked at those little two-bit pins at annual inspection. The seat height adjustment relies on an acme-threaded rod, rotated by a crank, in a machined aluminum nut. That nut's threads wear out and tear out and the seat suddenly drops to its lowest level.
Your 172B seat likely has one locking pin, so only one seat rail has the pin holes drilled in it. 172M's have two locking pins, and both rails are drilled. Now you're looking at more mods and more 337s or whatever.