Thanks, that helps a lot.
Thanks to all...
Update: the grip is Not wood, rather it's very dirty m(or painted) ivory, more like Bryce's pics. The owner found the whole assembly was loose and the peening had failed and they were able to disassemble the remains. the blade tang is additionally stamped either WH or HM. The cartouche may be an HM (or a WH

)
Other side of tang to document the GG stamp also added.