I also vote for leave it alone. Dust it off, treat it gently with a bit of lemon oil, and admire the ingenuity. If you want to play it and are worried about the stresses, consider tuning it down to the key of C (CGG, CGc) rather than up in D, with the same gauge strings. That should alleviate some stress.
I've seen a number of old dulcimers which used a violin like "tailpiece" such as this, and I must say adapting a bottle opener to that task is genius!
Will, the more I look at these pictures the more I feel you should not alter it but leave it as it is. In many ways it is so unique. This is an excellent example of someone making a homemade instrument with their own ideas of how it should be done... right down to the bottle opener tailpiece.
As of right now, I think I will keep it the way it is. I can play it somewhat, but there are some cracks on the tailpiece and scroll that make me scared to tune it very high. It sounds a lot like a banjo, I will try to get a sound sample of it soon!
You have a treasure there William, it was built very ingeniously.
Will you be making it playable or are you going to keep it originally unique?