It does resemble an Alpha vaguely, but there are too many differences to be a cut down 4.4 AO. There is way more "roll" from the deck to the hull wall than an Alpha has and there isn't anywhere near enough rocker, also the AO 4.4 has three beams not two and none of them are round, the transom shape that shows the profile of the hull is quite different as well. The deck line on this cat is fairly straight from the bow to the rear beam whereas the Alpha "stepped" (quite noticeably) at each beam mount
You say that you had a brochure? So I presume that this cat was originally sold commercially? If that were the case then you would expect that there were more than just this one made. It looks from the photos like the hulls were made from a female mould. That being the case then some one has put a lot of time and money into the project and you would expect SOMEONE to know just what it is. It has me stumped though.