I made my own fantastical Polaroid back for my Holga cameras. Sure, I could buy one (for $180) but I could also just take my Dremmel to a broken super shooter plus and a Holga back and make my own for the mere cost of $30 (with 2/3 of that being new Dremmel cutting discs), so that is the route I chose. In a few fun-filled hours I had repurposed franken-camera, and I learned that safety glasses are never as good as safety goggles. My scratched cornea that also came out of my camera modification adventure is healing nicely, and I solemnly vow to only wear safety goggles from here on out.
The final camera does have a very short focal range, which has to do with the film being about and inch further away from the lens than it would be in the normal Holga (you can rectify this by using a different Polaroid model, like the land camera series) but it’s still quite fun to play around with, and I’m sure I’ll figure out the best way to use camera eventually. That’s part of the fun of it, isn’t it? The trial and error, the experimenting, the surprise when you pull apart the developed instant film. You certainly can’t do that with digital! I’ll keep you posted.
If you decide to make your own Holgaroid, please do know that Polaroid stopped making film a few years ago, but Fuji has taken on making the 100 sized instant film, as did the Impossible Project (they also have other sizes of instant film as well). You will need to make sure that the old Polaroid you are making your Holgaroid out of is compatible with 100 sized film.