[Moon] Damage and repair to Alpha horn?

[cn85be]

Aloha to all:

I have a conical horn that must have gotten dropped/dented and caused a 
flat spot on the edge of the horn. The material is thick through out the 
body and machining could restore the horn without breeching the 
exterior. My question is would it be acceptable to simply machine out 
the inside again restoring the internal shape of horn even though this 
would result in the material being thinner in the region of the original 
flat spot?

I am not using it for any precision testing, but would like to use it to 
illuminate a parabola if it's repairable. Will it have some funky spill 
of to one side? This is a long narrow conical for Cassegrain feed

Mahalo in advance,    Jeremy w7eme