That's just one of the old nylon mounts and they are soft. The plates LN is showing will do the trick. Fire wall holes are easy to fix, just drill them out to the size of a dowle and epoxy in the dowels in all the holes and you have a new fire wall after you epoxy over them to fuel proof. Thrust angle is something I work out during trim flights and I make up shims to go behind the mount like Rock mentioned. What degree the thrust comes out to I haven't a clue. At the field I use washers to find the thrust angle the plane needs then when I get home I measure and make up the shim.