You're quite right Sid, I missed the 131 abarth reference the first time round.
I think the B could also refer to the series of engine, as I believe it was the 131 B2.000 series used in the 131 Sport. To the uninitiated pulling a gearbox off of this engine that had Abarth cast into the linkage casing could lead them to believe that the engine was Abarth too - which of course it is not.
I wondered about the blurred pics too, and why post pics at all if they are this poor
.
Lots of things point to this being an 8 valve tho, not least the position of the dizzy. Also the cams are too far apart.