Thanks again. Re the 199A, Canon flashes of the period had a unique (?) two prong camera-to-flashgun cable fitting, which I no longer have, so I'm reliant on shoe-to-PC cables of various kinds. Benjiboy, I appreciate the flash will work with any camera via the central pin, but A-series Canon's had an extra contact for TTL metering, which would not function via the Voigtlander's PC socket, obviously. Are you saying the 199A is independently automatic? I usually set the flash manually.
One question as an aside, when I use dedicated flashguns off camera via a cable (but with the appropriate camera), should I use the gun at the normal 90 degree angle with the front flash sensor pointed towards the subject, or doesn't it matter? I find it easier to use the flashgun "flat" (locked at 180 degree position) when off-camera, but fear the flash sensor is pointing in totally the wrong direction, usually toward the photographer!