a lot of the papers at that time period were silver chloride / gaslight papers and prints were made by contact printing.
122 film was a roll film used in folding cameras as well as "post card cameras" like the 3a graflex .. other large negative
cameras that either made glass plates or used sheet films were often used.
5x7 was also a loved format of portrait photographers of that time period ... but any large format camera bigger than 4x5 could have been
converted to have a smaller back or a sliding back to allow for multiple exposures on a larger negative ... which then could be contact printed.

good luck with your project, sounds like fun -