I can tell you this...that cab isn't dedicated.
It's a Dynamo cab. Cut corner.
You should be able to find replacement panels fairly easily for it.
Wrong. For Double Dragon II it came in a dynamo cabinet. As did many games of that time (Street Fighter II CE). It probably is the original cab for that game. because it is a dynamo cab doesn;t mean it is dedicated. Just like midway and taito, they tended to use the same cabinet for all their games. At the time dynamo was the smart and cheap way to go. They mass produced jamma cabs for the arcade industry.
Finding parts for it isn't that hard. It is an older dynamo so some of the current dynamo cabinet parts aren't the same.
Finding artwork on the other hand is near impossible. I've been wanting to to get reproductions for my double dragon II cabinet ever since I got it.
Especially since there are two versions of the CPO. There's a tan and a white. White is nowhere to be found and I think the best looking. I see the tan show up on ebay once and awhile. I have the white cpo, you have the tan. White is a little more rare.
If you need an operators manual I have mine in pdf format.
For insurance info, this cabinet isn't worth that much. It isn't a very popular game to collect and it is a "generic" cabinet. Everything but the artwork is readily available and cheap. You can get replacement boards for $10 on ebay. I replaced my marquee for $1 on ebay.
Being that I own one of these I say preserve but make it a mame cabinet using jpac and arcadevga. Use something like multijamma to switch between original boards and computer. This is the perfect jamma cabinet, everything is to jamma specs.
finally the pics loaded for me, I hate modem. You have a cabinet in good condition, I wouldn't do anything to it to harm the artwork since it is hard to find replacements for ddragon2.