My BIL needs some special parts made, and I'd like to help him out.

He has lights on his dune buggy that are mounted with a threaded rod through
a round base. The base is flat, but when the light is mounted to the roof,
the roof is slanted, so the lights shine down too close in front of the
buggy.

I need to find a piece of solid round aluminum or hard plastic or nylon that
I can drill a hole through the center, then slice off portions with one side
at ninety degrees, and the other at the proper angle to make it a tapered
spacer to bring up the light beam. Anyone got a piece of solid nylon stock
1 1/4" diameter, or aluminum the same diameter, or can tell me where I can
purchase such a small amount? Round would be nice, but I could also do it
with a piece of square.

There are three lights, and it would take three inches at max, but would
like a larger piece to be able to hold it in the band saw to cut the angles.

TIA

Steve