The transom top on the destroyers isn't level so fitting an aux without a bracket is not possible (not on mine anyway!).
I did the below, made form a few planks of oak, glued and screwed together then coated in epoxy resin with a glass matt back face (which probably wasn't needed). It mounts using the same bolts as the a-frame to save drilling the transom any more, although I had to replace the originals with longer ones.
Both engines are long shaft. The main engine is offset just over an inch to stbd.
This setup gives full steering of both and works for me. There is no flex or slop like I used to get on the old adjustable bracket. I'll agree it needs a lick of paint though.