1919 by the serial number. Missing the crystal, the back case is hard to screw all the way on, seems like someone had pried the back off at one time. Doesn't run, seems to be the spring on the wheel. The wheel flops around, As you might think, I'm not a watch repairman.
The dial is 1 3/4 across, I don't know the size. On the back movement: Adjust Temp. & 5 positions, double roller, Illinois Watch Co. Springfield, Motor barrel 19 jewel Serial 3565769. 1919 ILLINOIS POCKET WATCH 19 JEWEL/Bunn Movement/10Kt GF Case/Parts or Fix" is in sale since Monday, November 06, 2017.
This item is in the category "Jewelry & Watches\Watches, Parts & Accessories\Pocket Watches\Antique". The seller is "roxene59" and is located in Newcomerstown, Ohio. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Russian federation, Israel, Mexico, New Zealand, Singapore, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Chile, Colombia, Costa rica, Panama, Trinidad and tobago, Guatemala, El salvador, Honduras, Jamaica, Antigua and barbuda, Aruba, Belize, Dominica, Grenada, Saint kitts and nevis, Saint lucia, Montserrat, Turks and caicos islands, Barbados, Bangladesh, Bermuda, Brunei darussalam, Bolivia, Ecuador, Egypt, French guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Cayman islands, Liechtenstein, Sri lanka, Luxembourg, Monaco, Macao, Martinique, Maldives, Nicaragua, Oman, Pakistan, Paraguay, Reunion.