Is this a car that possibly was sold or driven in California? It looks a lot like the remnants of a NOX sticker (Kar-Kit NOX system? if I recall?) I had to have the kit put on my 67 when I went to get my first smog inspection in the late 70's. The kit consisted of an underhood sticker, a dash sticker and two rubber caps for use in place of the vacuum advance hose on the distributor. I cannot remember the years of cars requiring a NOX kit (there were several other types on the market ~smog shops sold them on cars which the state determined needed them) but something says it was like '59-73 (cars before Catalytic Converters)
The installer of mine handed me back the vacuum hose he removed (and capped off), with a wink, saying it runs better when put back on.
NOX is a pollutant created from spark detonation (octane ping) and retarding the ignition timing was a "quick fix" idea used to help with tailpipe emissions. In the 70;s, California had not yet switched to using a Dynamometer while testing cars. You couldn't test a car for NOX without a dyno so the quick-fix was run all non-cat cars retarded. (realize that during the 70's, a vast majority of cars on the road were these 59-73, non-catalytic cars)
Sounds retarded, yes? Well, so were your cars! They pushed the timing back a couple of degrees from spec and removed the advance hose! Throttle response went WAY gown and gas consumption went up and because of the retarded timing, exhaust heat also went WAY UP (picture "glowing red"), thus burning off the extra fuel dumped into these non-catalyst converter cars which were a huge contributor to the smog of the densly populated areas of the State of California.
This crap also promoted sales of the newer cars, (who wants to drive a sluggish, gas-guzzler during an energy crisis?)
A real win-win for the EPA!
YES, RETARDED!