So Firepower or others? Are the SA3 letters critical too? I assume the DC means you need a diode?
Will any of these do the job?
AE-23-800
AE-23-800-2
SGI-23850-DC
SA3-23-900-DC
From
http://www.pinballmedic.net/coil_chart.html -
Williams Old Coil Number to New Coil Part Number Cross-Reference Chart
SA-23-850DC ~ AE-23-800-01
SA3-23-850DC ~ AE-23-800-04
SA2-23-850DC ~ AE-23-800-05
SG-23-850DC ~ AE-23-800-06
SA4-23-850DC ~ AE-23-800-07