I usually come to Canon Service Center in Makati for my Canons. So I suggest you visit the authorized service center for your cams. Olympus is a popular brand and it shouldn't be that hard to google its service centers. Yashica, on the other hand, is not as popular these days.
But then there's Columbia Photo in Araneta Center (this one's located in the old Rustan's mall, beside JB music) who repaired my Light Meters. I inquired about a restoration project for my old minolta, canon and Olympus 35mm film cams and lenses. The claimed they restore most brands; even obscure brands like Holga! Why don't
we try it out?
By the way, nice Rangefinder you got there. I have an Olympus OM-10 Rangefinder too.