You need to find better workshops or atleast get everything done in one go.
Such work usually starts with a thorough inspection (which usually is done by car owner if owner has an old and rare car)
List all that is not complete/original and find parts, lubes, chemicals, cleaners etc etc before having the jobs started, otherwise you will be permanently visiting mechanics forever every day of your ownership.
A good car should be more on road and less in repair, not the other way round.