A Guide to Illinois Watch Co. size 12 Watches, Grade 503.
Run.
Date
From
To
Total
H/O
Jls
Adj.
Run.
Date
From
To
Total
H/O
Jls
Adj.
1
1915
2,799,511
2,799,520
10
O
15
Unadj.
8
1917
3,144,001
3,144,500
500
O
15
Unadj.
2
1916
2,889,001
2,889,300
300
O
15
Unadj.
9
1918
3,242,001
3,242,500
500
O
15
Unadj.
3
1916
2,896,401
2,896,700
300
O
15
Unadj.
10
1918
3,382,001
3,382,400
400
O
15
Unadj.
4
1916
2,901,601
2,901,900
300
O
15
Unadj.
11
1918
3,424,001
3,424,100
100
O
15
Unadj.
5
1916
2,998,001
2,998,500
500
O
15
Unadj.
12
1919
3,468,001
3,468,400
400
O
15
Unadj.
6
1916
3,011,001
3,012,000
1,000
O
15
Unadj.
13
1919
3,476,601
3,477,000
400
O
15
Unadj.
7
1917
3,089,001
3,089,500
500
O
15
Unadj.
14
1919
3,537,001
3,537,300
300
O
15
Unadj.
 
  Total
5,510
 
Grade 503 runs.
Serial numbers used on this page by the kind permission of
Russell W Snyder
Last update 12/22/2015.
Grade 503,
15 ruby and sapphire jewels unadjusted, manufactured from 1915 to 1919 a total of 5,510 movements in 14 runs make up this grade. Model 4 size
12/14 open faced; bridge movements of medium quality, single roller and patent micrometric regulator.

Observations,
The movements have broad striped pattern demaskeening named Hallmark. The size 12/14 movements have a size 12 bridges and size 14 pillar plate
and have a stretched enamel dials that are not recessed into the pillar plate, they require special cases.

Description,
15 ruby and sapphire jewels; oreide settings; spring tempered compensating balance with timing screws; hardened and polished steel escape wheel;
sapphire pallets and jewel pin; polished gold center wheel; patent Breguet hairspring; micrometric screw regulator; safety screw center pinion;
concave and polished winding wheels; safety recoil click; demaskeened broad striped pattern; gold inlay engraving; unusally large dial is a special
feature of the watch.
Image of run 9.