Joseph,
I do remember the change over from 35mm rangefinder to SLR in the amateur market.The camera shops used to be full of rangefinders such as Yashica Electros (see link:
http://www.yashica-guy.com/document/chrono.html), Canons, Minoltas and Ricoh's.
Poor Yashica. I had several of their compacts having changed from an Ilford Sportsman. I see from the link site that they manufactured the 1960 Polaroid Land 120. How are the mighty fallen. The "compact" rangefinders in the shops around this time were the new automated ones. "They were very good too but then the SLR began to become affordable and although Nikon and Pentax ruled the roost with adverts by David Bailey, I found I could afford a Praktica in about 1968. I stayed with Praktica for many years until I returned to Yashica with an FX3 in 1984 which was the beginning of my expensive affair with Contax.
After subsequently buying a 139, I have only deviated from Contax once since then when I sold everything to buy a Mamiya medium format outfit. But withdrawal symptoms meant that I needed to rebuild a Contax outfit.
I often wish that I had kept all my cameras and lenses over the years but lack of funds meant that, like most people, I had to sell them to fund new purchases.I do however still have my first camera which is an Agfa Clack. Very occasionally I use it as it takes 120 film.
Sorry if this is more like a note of personal nostalgia but in retrospect it was an interesting time although when the transition was happening, I don't think I really noticed it as such.
The compact market never faded away. Just as today when there are myriads of small digital cameras, there were many constantly improving compacts available and they made excellent photographic companions.
Leica rangefinders apart, the SLR became the camera to aspire to for "serious" photography just as the DSLR is now although it's possible that the DSLR may be superseded by cameras like your R1 and that would be a real transition and revolution.
Thanks Marc for the well researched and interesting post on the development of the SLR. I hadn't heard of the Soviet GOMZ Sport; fascinating stuff.
John