That's a nice looking wrapless titlist conversion. There are several cue makers that have used that ring work. I would suggest compiling a list of those cue makers and then start to run down a list of comparative traits such as shaft pilots, joint pin type, weight bolt type, and bumper. That should shorten your list down quite a bit. Then call the remaining cue makers and talk to them to see who might have made the cue. If you get a hit, then send in the cue for authentication.
The wood looks aged, so I would keep the list short to cue makers that have been working 15 years ago or older.