There once was a time when there was only one kind of Contax I, II, III, IIa or IIIa and this was a factory fresh unit. But about 50 years have elapsed since Zeiss suddenly announced the end of rangefinder camera production. Since then every Contax IIa and IIIa has obtained a history of source, use and maintenance. Today, when a person sets out to find and buy a Contax IIa or IIIa, these factors need to be kept in mind in order to avoid cameras that have a bad history.
When Zeiss announced the end of Contax IIa and IIIa rangefinder camera production it came suddenly and without any notice. A catalog was issued to announce the start of the Contarex line and this catalog announced the end of rangefinder camera production and then end of all lenses and accessories for rangefinder cameras. At that time the Contax IIa cost the same as a brand new Chevrolet automobile. It was not just a "big ticket" item, it was a "huge ticket item" and there were people who had scrimped and saved for years to have one. The sudden demand was gigantic and dealers screamed to the distributors for cameras. In response to this demand spare parts were scavenged from every repair depot to produce cameras for sale.
A Contax I, II, III, IIa or IIIa camera is hand made out of hand made parts. This means that the parts from one camera will not necessarily fit into another. There are very wide differences in parts sizes from camera to camera. When cameras were made at the factory the assemblers had a very large assortment of parts from which to choose to assemble a camera. But when the spare parts or multiple parts cameras were used there were not so many parts from which to choose and some cameras were made that could not possibly work right.
Another element of complexity that enters this mix is that Zeiss introduced many internal changes to IIa and IIIa parts during the period of production between 1950 and 1964. There were three improvements to the mid range speed controller, five improvements were made to the rangefinder module, parts which were once bare brass became nickel plated, gold prisms were changed to platinum, the shutter tape was changed twice, all these are to name but a few. When a camera was made out of spare parts, parts from every time of production were incorporated into the camera resulting in a camera made out of parts that reflect the entire production history. So for a person like me who sees a great many Contaxes they are not at all difficult to identify.
The Contax IIa and IIIa are so valuable today that people are engaging in the same process now. Non working cameras are purchased at a low price so that parts from two or three of them can be combined to produce a high priced Contax for sale to unsuspecting victims.
My experience with these repair shop made Contax IIa and IIIa cameras is that they are always a lot of extra work and trouble to make right.
The question is, how can one avoid becoming a victim of a modern greedy camera butcher who is busy manufacturing Frankenstein Contaxes? The answer is that sometimes it's easy and sometimes its not, but it can be done and here are the main things to look for to avoid being stuck with a Frankenstein Contax IIa or IIIa:
The situation with the Contax II and III is different from the IIa and IIIa. The main problem with the Frankenstein models of these cameras is that a well used Contax II or III can be considerably improved by the use of russian made Kiev internal and/or external parts.
The Contax II and III shutter is very very tricky to overhaul successfully. If a person is in the business of selling prime looking Contax II's for a living, and money is the main motivation, it is just faster and simpler to throw out the German shutter and put in a russian made kiev shutter. And the people who do this also have no problem turning a $40.00 Contax III into a $500.00 Contax II by simply taking the German made III light meter top off of the body and putting a $25.00 russian made Kiev Contax II type camera top in its place. In this way it's easy, cheap and quick to turn a well used Contax III that doesn't work into a faked up Contax II that looks good and is about 50% kiev.
There is no way to diagnose a Kievontax externally. The one and only way to do it properly is to examine the internals for signs of russian workmanship. When the russians made a camera they put 99% of the production cost into the exterior surface and so from the inside they are quick and easy to tell from true German manufacture. Given this limitation there is one and only one sure and certain guide to avoid purchasing a kiev in disguise and so here it is:
"The camera is 100% original German Contax, contains only parts that were used to manufacture it originally, and the seller will accept the determination by Henry Scherer that the camera is not genuine without argument and will promptly issue a complete refund including all shipping costs if Henry Scherer examines the camera and finds it contains parts that are not genuine original German Contax."