Stringing Mystery on Vintage Dulcimer

Hi! Not sure where to post this, but as I am new to dulcimers in general, I thought I'd start here. I recently purchased a vintage dulcimer from an antique shop and am attempting to get to know it. It seems to be playable but has some weird features.

One of the things that is kind of freaking me out is the string and groove arrangement at the bridge (see photo). The dulcimer seems to have been designed as a 3-stringer, because it only has 3 wood tuning pegs, and no room for a fourth.

When I bought this, it came with a receipt from the local violin shop for recutting the grooves, replacing a string screw and restringing. Keeping in mind that it is currently strung left handed, which I need to fix, what do you think happened here?

There are 4 screws and holes in the bridge, but only three pegs to match -- and the four little lines you see around the three grooves currently in use appear to be either just pencil marks or practically nonexistent grooves.

Obviously the angle of the strings over the bridge also has me wondering -- does it matter? I can currently tune all three strings to the same key (haven't gotten my tuner yet), and they play fine -- the only problem being I might need peg dope for the pegs to hold more solidly, or have a luthier assess them.

Thoughts? :)