Chuck,
I think you are wrong about at least two things in your message about Sediscolor chains. The PX 60 that you cite as an instance of a Sediscolor chain on a 1975 bike in fact has a replacement chain. Here is a picture of the bike in the COVER of the netherlands catalogue for 1975, with a BLACK chain.
http://home.wanadoo.nl/
I checked that bike out before making my assertion that SedisColor is a "second half of the 1970's thing".
The second error in your message is the assertion that Peugeot did not list chain types in their catalogues. Here is catalogue page that DOES list a Sediscolor gold chains as part of the bike, e.g. :
http://home.wanadoo.nl/
If you have some evidence of a picture of a bike or a catalogue that lists a Sediscolor chain then I'd like to see it. You don't even have to show me the specifications, if it's a peugeot or a motobecane with a gold chain and french drivetrain then i'll assume its sediscolor.
I stand by my assertion. Sediscolor chains are a "second half of the 1970's" phenomena.
- Don