Hi,
This is an interesting question and involve money, as I see it.
You can buy 39mm film bodies cheaply like the FED 2 but they only take screw thread lenses. There are some M bayonet bodies out there that are also cheap. By cheap I mean cheaper than a digital body and adapters.
Film is cheap because you get it developed and printed for a very reasonable price. Try working out the cost of a print from a computer and you'll see that the three dozen or more prints I get from the lab are dirt cheap. Cheaper still, get the lab to develop and scan only. My one charges about three pounds for that when I'm testing a camera and don't want the prints. And they are "full frame" as well. And film is cheap if you look around.
Years ago I had a serious pro digital camera, used it and then sold it. Each file I downloaded from it was dearer than the film, developing, scanning and printing I got from film, per frame. Add the cost of printing and so on from the digital ones and you'll be shocked. Mostly because of depreciation. Also film cost make you think about the shot, with digital you take several and print one; so film tends to teach you more than digital ever will.
Lastly, a second hand digital and so on will have few pixels and limit the print size. 35mm film is not limited like that, and there's slides and so on...
Just my 2d worth.
Regards, David