There were two Carbon Wind Actions brought into SA by SA Sailboards . They were custom ordered by Two Dentist ( Bob and I Can't remember the other) who used to upgrade their boards all the time, they sailed off chicken shop in the mid nineties. One was 275cm and the other must be the one you have .
Around 1995 I bought second hand the 275 and that was the fastest board at Lake George in 1996 . It was around 100Lt nice sharp rails, Pin tail , stiff and durable, Cruised up wind, It has a powerbox and the mast track is about 5cm too far forward. It was one of my favourite boards, probably because I was at uni and I sailed so much back then. After that board I tried Copello's, Fanatic's(First carbon falcon imported in the 90's),Caveman, Drops, StarBoard's,and the Mistral SLE the Orange ones none of which I enjoyed as much as the Windaction.