I am not obsessive about about having period correct parts so I don't see a problem, and as I don't ride my 84 team miyata that while not original is close (friction etc) as much as I ride my 85 team Miyata (with modern 105 11 speed) I don't think I will wear it out.

I do think that at some point in the future if I have problems throwing a leg over the bike is an issue a custom mixte would be the answer to keep me riding

other wise I try to ride as part of life (commute, errrands) and treat long rids a bonus time

of course losing 50 pounds or so will help