Well then, that being the case, you don't have anything to lose by trying some light gauge mandolin strings on it, and see what you get. You could start with mandolin tuning, but you will find it too floppy to be playable. then just sneak the tension up a bit at a time, until you get a playable note. Then see what notes you have. I bet cgda would work, a 4th above mandolin, when using mandolin strings. What do I have to go on? Absolutely nothing! But my guess is as good as anyone else's at this point. If this thing was mine, that's how I would proceed. YMMV.The top and back are both fully braced--top has at least two (one just past the end of the fingerboard and the other under the bridge area; two on the back-one visible through the sound hole and one across the lower bout). The strings are not permanently attached in any way and are "real musical strings" (but very old). See images below. I do agree that the peg winding is not "professional" but I don't think that sheds light on the issues at hand.
What a kick it would be at a gig to put away your regular axe, pull this out from under your coat, and start wailing' on it!