I did a little digging and found a similar crossed arrows marked bayonet on CollegeHill Arsenal. Here is the quote in the description, "The blade is marked with the usual
US mark on the ricasso over the enigmatic mark of a pair of
{Crossed Arrows}. This scarce marking variant is shown in Robert M. Reilly's
American Socket Bayonets & Scabbards as Figure
B78A. The meaning of the mark is not known at this time." Seems like Tim Prince is even stumped
Link:
https://collegehillarsenal.com/Rare-Crossed-Arrows-Marked-US-Model-1835-Socket-Bayonet