23 jewel E.Howard Keystone pocket watch. Display Case.

Fairly rare watch this, the movement was manufactured by Waltham for E.Howard Keystone Watch Co. sometime around 1920-30 I would guess as I cannot find any references to this serial number on PWD or in the price guide. If you know then please let me know.
This is a very high quality movement that is very very similar to the Waltham Premier Maximus. It has 23 jewels with a fully capped Swiss Lever escapement, double roller, gold timing screws, Sapphire pallets, Diamond cap stones for the balance and lever, and a sprung micro-regulator. The watch also has gold (alloy) train wheels with a steel escape wheel, and a fully jewelled spring barrel. This is top specification for a watch of the period.
This one is mechanically sound as it's running strong in all positions and keeps spot on time within a couple of seconds per 24Hr. The watch is stem wind and stem set.
This movement is housed in a nickel display case that at some point has been gold plated. It has snap on covers front and rear, The case is in very nice condition with just a couple of small spots of gold loss.
Original Howard signed dial is in fair condition as there is a chip on the edge by the 2 with accompanying faint hairline, and the Howard signature is faded.
A good set of blued steel hands and two good mineral crystals.
Overall a fairly scarce watch in very nice condition, runs well.