Modifying an old cyl hone tank

[JRM]

I've got a tinker project and need some help. What I am working with is an old Hone-master Cly honing tank and I wanted to see if I could wire in a load meter to it.
I looked at the load % meters at Grainger and they are also showing a shunt (donut) needs to be wired in which has me a little confused.
The motor on the machine runs at 7.4 amps free wheeling and 10 amps loaded down @ 110 volts (that was a little feat holding the spindle from spinning to get a good reading)
Does anyone know how sunnen wires in their load meters and/or what parts they use?
Thanks
John