Link to picture: http://www.flickr.com/photos/1601022...in/photostream

I inherited this Kodak Autographic 3A from my Grandad. He has clearly adapted it ... for 120 film...? I wanted to have a go at putting it to work. I am a total beginner, and have a few questions. I hope you can help!
Do you think this has been adapted for 120 film?
If so, could you offer tips on loading the film, and, importantly, on how to know how much to wind the film on after each shot?

Will a commercial developers develop this film?
Anything else I should know?!
Thank you very much