Feedback welcome
Instruments- discuss specific features, luthiers, instrument problems & questions
John and Ken have already given you good advice, however, I'm going to add another one or two. First, from the photo the Blue Lion looks to be in good condition. It can use a good cleaning, but that's not a problem. I play my Blue Lion as a three string as I prefer that to four strings in any configuration. Second, I'm sorry you've had bad experiences buying used dulcimers. It can be frustrating. Like Ken said, we can help talk you through replacing a nut and bridge if that is all that those dulcimers need. There are resources out there for playing with four equidistant strings, both books and videos. I do think that most of them (if not all) require some knowledge about how to play the dulcimer.
Ken
"The dulcimer sings a sweet song."