with williams pinball coils the first number is the gauge of wire used and the second number is the amount of turns, i.e a 23-800 has 23 gauge wire and 800 turns
your coil 090-5005 is equal to a 23-840
the closest coil i can find is a stern 23-840
http://www.marcospecialties.com/product.asp?ic=090-5005-00here are the specs for the coil
Wire Gauge: 23
Number of turns: 840
Resistance in ohms: 4
