this category mainly focus on early wristwatches in enamel dial, they appear in many case construction, such as half hunter, full hunter, borgel, hermtic, semi hermetic, full hermetic, 8 days, direct read, chronograph, calendar, officer trench, left hand, 3 pieces oyster case etc.
examples in the picture is a 9k beautiful enamel cushion by rolex, NFS.
rolex silver screw back & front case
pre oyster case designed, early attempt for moistureproof and dustproof, silver hallmark case, getting hard to find this variation, nice enamel dial, case back engraved scre front & backsilver bracelet, 28mm in diameter without crown, in working condition.