Welcome LG1816!
It is Japanese so it's probably a very nice machine but I seriously doubt it's a Matsumoku product.
It doesn't share any build characteristics with any existing model at the time. Being an '87 model and knowing the state of the company, I doubt they would have built an entirely new model.
By '86 or possibly sooner, they were looking for ways to save money. Look at the "The Cat" guitars. They had plyw- uh, I mean, laminate bodies that were not shaped exactly correct. Now, I owned one and there was absolutely nothing
wrong with it but it wasn't quite what my other Mat guitars are. I still own the neck. It's one of my favorites and is currently on an '83 RS Special V body. I believe the necks were actually Mat made but the bodies were not. Nowhere on a "The Cat" does it say "Matsumoku" or "Made in Japan".
I believe they were contracted out to the lowest bidder.
Anyway, nothing against your guitar. It's probably a much better machine than "The Cat".