I just picked up this Wahl Eversharp mechanical pencil.
There are scores of these things available over the internet. The Wahl company began production of these pencils around 1915, and had sold over 12,000,000 by 1921.
This model - referred to as 'Gold-filled' (gold-plated) - is still surprisingly common. Back in the day there was nothing especially out-of-the-ordinary about this sort of pencil.
The standard of finish and quality of machining is high - this is a piece of writing art; functional but aesthetically pleasing. 'Henry' obviously thought it nice enough to not be in a hurry to lose it.
Now I compare it with my day-in, day-out Faber-Castell. Functional and sleek ... but I'd doubt someone will score this pencil in 80 years' time and wonder at its quality and design.
Ah, yesterday's standard!