This idea is from Gene at Troy Built Models

I can take some plate aluminum--1/8" thick--and cut it to bolt right on top of a HD DuBro plastic servo horn. Bolt the aluminum plate on top of the plastic horn, and just drill the offset holes out where I need them.

I need 1/8" offset.

In the pic I've attached--the black outliine is a DB HD plastic horn with 4 holes in it. The red line represents the aluminum plate that I would bolt on top. Use a couple 2/56 bolts to secure the plate on top of the plastic horn and them drill my offest holes out on the end.

Kind of a home-made Nelson horn.

Crude Paint drawing attached: [:-]