Horseman film back instructions/advice...

I've just purchased a 6x9cm Horseman back to fit my 5x4 cameras. Having not used one before I can't work out what the little siver "switch" below the advance lever does?

It's simple to load but I haven't been out with it yet. I'm thinking that it's maybe a release to wind on to the next frame but I haven't got that far yet.

Can someone tell me what that little switch does???

It's been a while since I had a horseman but maybe it's the multi exposure lever or a wind lever, as you guessed? If you can post a pic then maybe I can tell you. Or just try a test roll and it'll be clear!

The small switch/lever at the center edge below the film advance lever on my Wista roll film backs is the release to allow advancing the film. They are very similar to Horseman roll film backs. If you have a paper backing from a roll you've already shot, just re-roll that on a 120 spool and test the action.

Lee