Frank, thanks for agreeing with me about those old Ektars being great glass. Single coating isn't any major problem with the simple designs and few air to glass surfaces on those lenses.
Many of the common view camera lenses are symetrical designs, what the Germans used to call a Doppel Anastigmat. There's usually a triplet behind the shutter and another in front. If you unscrew the front lens cell you can use the rear one by itself, about double the focal length of the complete lens. Where the front and rear cells aren't the same focal length you can also use just the front cell, but supposedly it's best to put it in the rear with the bare shutter blades/diaphragm in front. Some shutters were marked with two or three aperture scales, for the complete lens and the cells alone.
The lack of "filter threads" was of no concern in an era when most photographers used push-on "series" adapters with glass series filters, which might range from tiny series IV to huge series IX.
A lot of the shutters (mostly American) from that era had what we would consider "non standard" synch contacts, probably to avoid patent infringement problems with Prontor Compur (inventor of the common PC synch contact). The most common was the bi-post, consisting of two rounded tip pins coming out of the shutter that fit in two holes in the end of the cord. A lot of these shutters have been crudely "converted" to PC by soldering the wires from a short piece of synch cord with a male PC terminal on it to the two posts on the shutter. There were another couple of types but you aren't likely to run into any.
Schneider Symmars are symetrical lenses, as is that fabled 203mm f/7.7 Ektar. The other Ektar lenses are mostly all four element Tessar designs like the Schneider Xenars and Wollensak Raptars. Just think how dark your ground glass will be with that Kodak Ektar using only the aproximately 406mm focal length f/15.4 rear lens cell...and NO autofocus!
