I don't believe that there were any fixed-lens rangefinders made in the focal range you're asking for, except for medium-format cameras (but those are not telephotos for their film size). However, many of the fixed-lens rangefinders were available with accessories including both wide and telephoto adapters and an external viewfinder. These were designed to be screwed onto the filter threads of the camera like a lens hood, or they slipped over the lens barrel and tightened down with a thumbscrew.
There were also 'universal' wide/tele sets made by independent companies that were supposed to be for any brand of fixed-lens rangefinders - you just matched up the lens barrel size or filter ring size.
The usual 'wide' was around 35mm effective, and 80 to 85mm effective for teles.
I would say that if you want a wide/tele adapter, try to get a set made by the same manufacturer as the camera - it will probably be better tailored to the characteristics of your prime lens. Yashica was a company that made a lot of accessory sets for their Electros, Aires was another - so those are frequently seen on eBoy. Make sure you get the external viewfinder as well.
Another caveat - most of these do NOT focus with the coupled rangefinder anymore. In fact, they have 'conversion tables' that turns your coupled rangefinder into a scale-focus camera. You focus using the rangefinder, then look at the distance marked on the lens itself. Then, you look up the 'conversion number' on the table that comes with the lens and reset the lens distance to that number instead. One has to be careful - some accessory wide/tele sets came with a piece of paper that had the tables printed on it - others came with the table printed on the accessory lens itself. If you get one that needed the paper and you haven't got it, you're sunk.
Last thing - in general, people seem to agree that these wide/tele accessories are not very good, sadly. If you need wide/tele, you're probably better off buying an RF with interchangeable lenses. If you must experiment, go with the manufacturer's own set if possible, and make sure you have the conversion tables and the accessory viewfinder as well.
Best Regards,
Bill Mattocks
