I've been at this a while now, and with the help of many of the forum members, I think I've finished it up. Gaze upon its wonder:

Looks pretty stock from the outside. The internal conversion was quite simple. Remove a bit of hardware and you get a nice film chamber. From there it's just a supply-side spool holder, and a takeup-side film advance mechanism. Oh, and a frame counting window.

I used a hanging folder tab for the red window, we'll see if that works out. For the advance, I used a key from an old Kodak folder, and a bolt with a spring for tension. One of the main problems with these cameras is the massive amounts of light they leak. Hopefully I've taken care of that with a full-body foam. I also isolated the takeup chamber with cardboard, since that seems to be where the majority of light comes in.
I may do a bit more work, including film transport guides and perhaps a 6x9 mask, as it takes 6x10 frames right now.
Results to come in the week ahead...