Okay! I will call on Monday BAS and ask them!
As far as I know you will have some problems with this apron, because the collector (Is it the right word? The part between the heads and the exhaust) is too big and you might have to cut some metal on the inside of your apron.
I had this problem with the BAS Type 1 exhaust and I changed the rear apron to a 1975 1303...
Now I drive a GWD3 exhaust
Btw: Your apron is called in German: Flaches Abschlussblech
Norbert