[Translation of the original French comment]Tecma started building the boomerang, then designed the Boomerang fz (at the time, Walbec had broken the distance record with it) and finally the boomerang XM which had 4 battens less than the others. The fz model was available in 2 sizes, 135 and 147. i still fly a fz 147.
The one on the photo is a fz. Easy to recognize, because early boomerangs had a B sign in the middle of the Tecma logo. And not this one.