MAGNUM downthrust?
 

1st gen Weston UK Magnum & Dub Jett 50

I fit the Jett to the mount and there is about 5 degrees down thrust,
the gap between the spinner and the fuse seem to be quit large at the top compaired to the bottom.

any ideas?

RE: MAGNUM downthrust?
 

Check for blobs of glue on the firewall... my first gen Magnum needed a touch of Dremel to get it straight... glue must be cheap in China :D

Also, don't trust the alignment of the wooden nose ring to judge your thrust angle. Mine was off too, but to the side.
The firewall itself appears to be angled correctly IMO.