Yes I think it's almost horizontal but I'm not 100% as I don't have one in my box of bits that's my bike
sorry, I got the wrong diagram, there is another fairly lengthy thread on here where someone has said there are two versions of this tap, and that it can be different to the SS tap of the same year*. They turn up on EBay new but possibly the wrong one (in this case). *I can't see why they would offer two similar versions at overlapping build-time to be honest - i can understand that they might add a different adaptor to accommodate a different thread on the tank, but apart from this..
surprise surprise, I didn't look far enough - here it is* :- Listed as Pt No:- 58840071A-Z 19.80 Euro + postage from Stein Dinse. (link below) https://www.stein-dinse.com/en/ducati-petcock-400-600-750-900-monster/item-1-1429437-1398-2.html *i'm getting Deja Vu here, on this Forum.
Thanks - just spotted this - typical as the one I purchased is the wrong kind and now I need to get SD to supply one of the above