My favourite Blogs and Youtube channels with lots of reviews of vintage cameras and lenses:
Much research, tests and reviews of vintage lenses, especially for use on digital DSLR cameras can be found on the comprehensive site of Vintage lenses for video
The Art of Photography: Ted Forbes and his reviews with videos about photography.
Zenography: Thoughts and reviews of cameras and lenses both old and new.
Mike Eckman (where does he find the time to review everything?)
35mm cameras (comprehensive database)
Interesting tips & reviews for Leica cameras (vintage and new) from the spontaneous Mr.Leica (Matt Osborne, and it is not all about Leicas).
Reliable vintage camera shops (no affiliation!):
Petrakla camera’s (Holland, all vintage cameras with CLA!)
Analog Lounge (Germany)
Digital Camera Graz (Vienna, a lot of vintage cameras as well, good service!)
DeWit Cameras (Holland)
Fotohandel Delfshaven (Holland)
Repairing or CLA for a Leica, do not hesitate, the legend lives in Holland: Will van Manen at www.kamera-service.info
And if you are patient, it will be rewarded on catawiki, every week hundreds of vintage camera’s and stuff.
And if you ever need a manual to one of your old camera’s, the most fantastic site belongs to Mike at https://www.butkus.org/chinon/ My compliments for this historic database of all camera’s.