Old mechanics have old rules for old bicycles.

Good engineering, and good mechanics, have the principle of least change: make the smallest change needed to achieve the desired outcome.

The principle applies to whole bicycles. Beyond a certain age, beyond a certain level of disrepair, do little.

Great old frames deserve rebuilding — if the customer has the budget.

But don’t over-write and overwork a beat-up bike. In the end, the customer could have better spent the money. In the end, the bike will take more work then charged.

Old bikes have unpleasant surprises: bearings that seemed dry turnout blown; cables reveal rust; etc.

Do the least possible — or do everything, and charge for it. Anything in between rarely works.