As already mentioned Retina IIIc, or IIIc-big, very good standard lens. Downsize, somewhat fussy to use, the lens and aperture are linked using the EV system, light meter is not coupled, the 80 and 35mm lens are axillary that replace the front element and are not coupled to the rangefinder and are somewhat slow. And not many techs will work on Retinas, shutter and rangefinders are complicated. I have a big C, that was given to me by my aunts in 1966, pulled it out of storage to run a few rolls of film but the low speeds are beginning to stick, need to find a tech.
Retina IIIS, very different than the IIIC, true interchangeable lens, uses the same lens used be the Retina Reflex, need to make sure lens has the rangefinder cam. Changing the lens changed the internal frame finder, from 28 to 123 coupled to the rangefinder, the 200 could be fitted but uncoupled, and you need the external 200 viewfinder. Shutter and light meter same as on the IIIC. Although not very modern it is possible to use the same lens kit on both a IIIS and a Reflex IV.
Canon IIIG 1.7 is a great walk around rangefinder, the lens is very good, has shutter speed preferred automation. Mine works well with hearing aid batteries. Lens takes standard 48mm filters, the light meter sensor along the lens so a filter covers the filters so you don't need to adjust your exposure. Lens hood are tricky, need a hood that won't block the rangefinder. Build quality is very good for a consumer grade camera.
Minolta 11, I have one of the later models the Super 3, 45 1.7 lens, as good as the Canon, shutter speed preferred exposure without manual override, takes 55mm filters.
Konica S3, likely the best lens found on any Japanese fixed lens rangefinder, 38mm 1.7. Total auto exposure, very small easy to carry around.
Petri 7, manual rangefinder no automation, basic light meter or early models without a meter. Hard to get repaired. Build quality is good.
Petri Color, not a rangefinder, scale focus, as small as a Rollie, lens is good, only thing I dislike is the battery compartment is inside the film chamber, if your battery dies in the field need to rewind the film to change the battery.
