Consult your schematic. What coil is supposed to be there? Check at https://www.flippers.com/coil-resistance.html and see if the resistance you measure is close to the resistance it's supposed to be.

Schematic again but 200 AC is most likely the right range (the red numbers at the upper right). http://www.pinrepair.com/em/index3.htm#low

Section 8.3: https://www.manualslib.com/manual/1113859/Sperry-Instruments-Dm-350a.html?page=6#manual
You'll need to know what coil you're measuring and what the resistance of that coil should be.
You'll find the information about what coil it should be on your schematics (or manual, if it has one) and you'll (probably) find the expected measurement at the link in post 2. If it's not there post what coil you have and someone will look it up for you.

http://www.pinrepair.com/em/index2.htm#clean

You won't find them online. Unlike every other manufacturer, Gottlieb claims copyright on their schematics. This means generally it's harder to get assistance with them because almost no one has documentation.
You can buy a copy from http://pbresource.com/mansch.html