This is the 3992B that passed through my collection;

Movement:

The whole thing:

Hamilton Model 28.

4C001

3992B SAMPLE 43

GCT White Dial

GCT White Dial Movement

If this database is still being updated, add mine:

PART NO. AN5740
MFR’S PART NO. 4992B
SERIAL NO. AF-42-5300
CONTRACT No.
W535 ac-28072
HAMILTON WATCH CO.

MOVEMENT NO. 4C49132
HAMILTON WATCH CO. U.S.A. ABOVE CENTER SECONDS WHEEL,
4922B 22 JEWELS (ROTATED 90 DEGREES ON PLATE) ADJ. TEMP. AND 6 POSITIONS BOLD ITALIC
CASE, KEYSTONE Base metal, 000581
DIAL 24 HOUR G.C.T. BLACK dial
WHITE HOUR MINUTE AND SWEEP SECOND HANDS