I've just got an old Raleigh GP back on the road and am loving every mile. However, in the back of my mind I'm worried about what the innards of the bottom bracket must look like. It's a 38 year old bike and I'm almost sure the BB has never been serviced.
Servicing these seems like a hornets nest, so I'd like to avoid doing it as long as possible and ultimately swap in a cotterless crank. Question is, what signs should I look for to detect an imminent failure? Given that the bike really doesn't have that many miles on it for its age (has basically sat in a garage for last 25 years) is it safe to assume I don't need to start worrying right away? Also please keep in mind that riding it until it breaks and then trashing it is not an option, as the bike has sky high sentimental value.