Dez sez
"I believe it is one of only two RF cameras ever made to have a true split-image rangefinder, the other being an obscure east German make whose name escapes me at the moment."
That would be the Carl Zeiss Jenna Werra.
Carl Zeiss Werra 3, Werra 4, Werra 5 or Werra matic. Other Werra models 1, 2 and Werra mat did not have rangefinders.
By the way, despite the name of the combinate - Carl Zeiss Jena - the Werras were not manufactured in Jena. They were assembled in a separate plant in Eisfeld.
Werra 1 - viewfinder only. No meter, no rangefinder. Fixed 50/2.8 Tessar or 50/3.5 Novonar lens
Werra 2 - viewfinder and uncoupled meter. No rangefinder. Fixed Tessar lens
Werra 3 - coupled rangefinder. No meter. Interchangeable set lenses.
Werra 4 - coupled rangefinder and uncoupled meter. Interchangeable set lenses
Werra 5 - coupled rangefinder and coupled meter. Interchangeable set lenses
Werra mat - viewfinder and coupled meter. No rangefinder. Fixed Tessar lens
Werra matic - coupled rangefinder and coupled meter. Interchangeable set lenses.
For the interchangeable lenses models, there were 3 set lenses available: 50/2.8 Tessar, 35/2.8 Flektogon or 100/4 Cardinar
There's various submodels available for the 1 - 1A, 1B, 1C. This is mostly about different shutter versions, in case of 1C also about an additional accessory shoe. Then there's submodels "E" of 1, 2, 3, mat and matic models, that's a newer "striped" exterior design and also accessory shoe. but speaking about rangefinders and meters, it's all the same as above with all the submodels.