See, the old timers took very good care of their equipment since they were making a living off it. Service on lenses should be once every 2 years and body once every 5. Backs got seals then too. Amatures use their equipment till it break down n then go get new used stuff n throw out the old broken. It makes sense if the repairs cost more than a replacement. So we are at the disposable age.
Your lenses are about 20 - 30 years old and have seen alot of action, yet they stil work fine for their age... care is everything. A CLA should take care of your problems.
Since you are a handy fellow n repair your Vespa, maybe consider trying to repair your lenses as well? It isn't hard and once you know how to do it, it becomes routine.
E-mail me email@example.com if you want to give it try? You never can tell this may be a new hobbby or an income.