Well in keeping with the sweat scrapers, the barn decided on giving out brushes (one brushes a horse to clean it, especially when it is too cold to hose them off), and that engraved brushes would be a nice gift for the upcoming dressage series. So the first one was a failure. The brushes have a stiff leather strap in the middle, and I taped it down. The brushes are taller than the honeycomb tray, so that worked out well, but the head will not clear the strap, so I taped it down. Not wanting to use gorilla tape as that might damage the leather, I used blue-tape. It popped off in the middle of the first brush… 
which caused the air assist nozzle to impact the piece, moving it mid-engrave…
(This was my fix test)
but then I used twine which was way more reliable and they came up super nice:
The second from the right has some residue on it from a price sticker. They were removed before I got them, but even with isopropyl and scrubbing I couldn’t get all the residue off. I didn’t want to use GooGone as those solvents would dissolve the finish of the brushes.