I'd only get a Tech III if it comes with one or more cammed lenses. The serial number on the top of each cam should match the serial number on the lens, and the serial number on the bottom should match the body. Without cammed lenses, it's still a nice, sturdy, precise metal field camera, but the possibility of using the rangefinder adds a lot of options that you don't have with other nice wooden or metal field cameras, like handheld shooting or more dynamic portraiture, where you can check focus using the rangefinder with a filmholder ready to shoot.

You don't need to have all lenses cammed, but having one or two lets you take advantage of that option.