I've seen lenses for Alpa 12 and Horseman SW cameras equipped with a little gadget that screws into the cable release socket on the Copal shutter to provide a convenient shutter release button for hand-held use. Here's an example:

www.alpa.ch/en/products/pictures/_l/ALPA_35XL-1.jpg

Does anybody know where I could find these? Neither Alpa nor Horseman catalogs it as a separately available item.