I have a 43-110 shaper with a flat head Allen bolt holding the bit. Which way do I turn to loosen?
It likely to be a standard right hand twist.
I'd love to see a photo of the shaft end in question. That sounds like an accessory that I haven't seen before (not that Iv'e seen all that many).
manual:
http://vintagemachinery.org/pubs/1141/19895.pdf