Miller,
While slower loading than a Mec et al., but for specialty loads where one isn't loading a flat's worth, the ability to handle shells of varying length without having to tweak a pie crimper for column height, etc, makes these vintage crimpers handy. There's a Bridgeport 12 RTO just under the red crimper on the left of the photo. Its pins are adjustable for either square or radiused crimp according to the writing on the German Silver crimper. Baffles me how it'd be done. It's set on square and it makes a nice crimp, but square topped. The ones made in the USA are easily identifiable; the French ones are more finished in appearance. It's easier finding subgauge crimpers from France than the in the USA where most are 12 gauge. 16 gauge seems to be the calibre de jour in France. ebay.fr "sertisseur". I have found several in 20 and .410 on the French site. More scarce over here.
Modern RTO's are available in subgauge from www.siarm.com (Italy) and from a Russian source I've seen on Ebay. Siarm's heads are gauge interchangeable on the same frame. Storage of RTO's obviously takes up less space than an assortment of MEC presses. Gil