John In Remote Kansas (JIRK) on LIK's cookie

I see that Malcolm Douglas beat me back with the comment that most early fretted-bowed instruments used gut frets. The gut was simply wrapped around the neck, usually while wet, and allowed to dry in place. Reports were that players spent a lot of time "adjusting their guts," but these reports come from modern players trying to recreate ancient music.
This suggests that you might be able to apply temporary frets to your violin, using something like large gauge fishline, or perhaps very small electrical tie-wraps, to get a feel for whether this is really something that will work for you. If you only fret for first position fingerings, the lumps on the back side of the neck shouldn't affect playing much, since the hand stays pretty much in one place.
If you have a nice fiddle, I'd avoid putting wet animal flesh on it, and would be careful about leaving anything in place for too long, since almost any "crack" can attract moisture, finger oil, etc that could damage the finish. Repairs to the finish are one of the most difficult (and expensive) things you can do to a good fiddle.
If you decide that you like the results from temporary "frets," fingerboard removal and replacement is a pretty standard maintenance/repair procedure. You could save the original fingerboard and have a new "fretted" one made. Of course, if you have a "good" fiddle, there is always a risk when you bust things apart.

John