The only data I can find here relates to the American Fiberglass (1962-1972) that built the Aqua-Cat. There was another, I think 1973-1977 or so' that made a range of small boats in the 12-18' range. They also made something called a "mini-tonner". I had a 16' daysailer with a windowless cuddy that displaced about 650#, with a steel swing keel. The construction was REALLY heavy duty.
There was(is) American Sail. Not sure if they are still in business. Originally a sort of re-branding of the Aqua Cat is what I thought. But I could be wrong.
As far as the daysailer that you are referring to: Did you see this link:sailboatdata.com/viewrecord.asp?class_id=5832
There are quite a lot of boats referred to as mini-tonners. Technically, it was an IOR rating that was a certain increment lower the 1/4 ton I believe.
I wish I knew more about the relationship between the 2 'American' companies.