Odd Dimensioned Brit Dawes Bayonet ID

[murph21]

Hoping to get some info on this 1700s British socket bayonet made by Dawes as it appears to have some shorter-than-typical dimensions possibly? Should I assume that means made for a carbine of light infantry-type gun? Doesn't not appear to me it was ever cut down but the underside fullers taper to almost the point of blade. Socket was split at some point. Here are dimensions.

Overall: 16-1/4"
Blade length: 12.5"
Blade width: 1" at widest
Socket length: 3"
Distance to back of sight slot: 1-7/16"
Current inside dia.: 7/8"

I believe the D over 9 on socket refers to the unit or company and/or row/gun numbers but more curious about the markings on the blade below the Dawes makers mark. It is a "4" (could this be a Regiment or is it an inspector's mark?), then a small "0" or "O" and then on the bottom it looks like a broadhead to me. ?? Hard to capture in pics but any info that could tie this to a specific gun, dates (Dawes-made), or a specific regiment (or commercial/militia e.g. non-military sales?) would be interesting. Realize that may be tough though. Found and purchased in US if that helps. Thanks in advance!