I'm not familar with that particular plane, but a few possible problems come to mind that you might consider:

1. If you flip the fuse over, will the elevator and wing incidences still be acceptable? If not you are going to have to modify the mounting somehow.
2. Is the wing fully semetrical or semi-semetrical? If not full symetrical, you are somehow going to have to match the top of the wing to the fuse instead of the bottom.
3. you will probably have to reverse the thrust angles on the engine mounting.
4. will you be able to re-mount the landing gear on "top" of the fuse and make it sturdy enough?

If all this works out, I don't think the dihedral or lack of it will matter much. Dihedral can help with stability and self righting of the plane, but this is not usually desirable on an areobatic plane. Just my 2 cents.