Can anyone help me find/measure/calculate the field inductance of an Elec-Trak Motor?

Hello everyone.

Can anyone help me find what the field inductance of an Elec-Trak 36V DC motor is?

The Elec-Trak site is down for maintainence, So I figured I would try here.

I will start with the motor make and model:

GE #5BCE56KB5B FROM AND ELEC-TRAK E-12.

The field resistance measures 15 Ohms acrossed F1 & F2.

I figuered I would try to find an answer here before I took the motor apart and measured the field coils etc.

Thanks.

Mike K.