@erratick Not a single marking anywhere. The guitar was a completely disassembled basket case when I bought it. All of the original pots, switches and the Tone Qube circuit were long gone. I do know the run of these particular guitars was approximately 1985-1989. I've seen photos of two with this trem. Both were supposedly from 1986. The later models I've seen pictures of are Floyd Rose equipped or hardtails.
I discovered a recent 15 second YouTube video of a guy trying to I.D. an identical one, but he's missing the pivot block. I've reached out, but haven't heard back yet. In reaching out on other forums yesterday, I've had two different people tell me that Fender had a similarly designed trem that was Kahler branded on one of their Japanese Contemporary Strat models for a short time in the mid to late 80's. Still haven't been able to find any documentation on that one, either.
@Peegoo, I posted on the RA Gresco Facebook page several years ago. It's actually run by Roger Gresco's nephew. He remembered the trem, but not the manufacturer.
The most frustrating part is after trying this search several times in the last couple of decades, a good portion of what I find on the internet at this point are threads I've started on various forums over the years looking for info. I pretty much always get the same guesses/answers. I just keep hoping that I'll eventually find someone who knows what the danged thing is. Regardless of what I do or don't find, thanks to you guys for the suggestions and help.