It's possible to mill off the handlebar clamps, but the casting is, for lack of a better word...hollow. Concave on the underside. Have a look at your spare and you'll see just what I mean, if you mill the clamps off, you'll cut right through leaving an open hole.
The upside is that there's a simple and inexpensive solution if it fits your tastes.
Mount the upper tree upside down.
Then paint or polish it.
-Alan