OK.....to clarify a few things.

1. Serial numbers pior to 1979. Peugeot didnt 'serialize' them as far 'we' (we being the bicycle community) can tell. Sometimes, 7 digits = 70's, 5 digits = 50's etc, but we've (we being the bicycle community) found that exceptions tend to be the rule. Because there are many known examples that do NOT follow any rules its always best to ignore the serial number and concentrate on frame/bike features to determine a Peugeots approximate year of mannufacture.

With all due respect to classicrendevouz they really need to remove or edit the serial number info on their PX10 page. Its just flat out incorrect.

2. Derailleurs: Simplex Prestige were mostly OEM on '70-'74 PX10's. Some of them were available with a Super Competition front and/or a Criterium rear derailleur. Im my opinion any of them would considered acceptable. Fronts, primarily plunger style Prestige but Super Competitions are OK. Rears, primarily Prestige but Citeriums are OK.

3. Lugs: Nervex Professional Model 49 or 'fancy' lugs were avaialble through at least 1974. It is a mis-nomer that they were NOT available in 1972 as I own 2 PX10's that are known 1972 examples and they both have Nervex model 49 Professional fancy lugs.

4. BB shells. Well, I was wrong about the OP's bike. I've been working on a theory as to why some PX10's have rivited serial number plates while others have stamped serial numbers. As best I was able to tell bikes with seamless Nervex BB shells got the rivited plates while seamed BB's were stamped. My theory was that the seamed BB's were too thick for riviting so they were stamped instead.

The OP's bike clearly has a seamless Nervex BB shell with a stamped serial number thus poking a giant hole in my theory.