Well, sourcing film isn't so bad. Simon and everyone at Ilford will cover you for that with their yearly ULF film extravaganza. But the holders might be a different story. I've never looked for WP accessories before, and I haven't seen too many offered anywhere either.
That bail back is interesting. It looks like only half a top and bottom spring each. At least compared against what I'm used to with my C1. But it does look workable—and working—in the photos. There must be someone here who knows more about this particular camera than I do.