Am changing the end that plugs into the wall and wonder if a 15 amp 125 volt is sufficient

Check the houing near the motor for a label, how many apms does it draw? Most are 12 amps or less so this should be fine. Where do you live that you see 125 volts?

I will asssume this is a standard house type vac. 15AMP is plenty. Make sure to follow the color coding of the wires. Black to dark or smaller blade, white to the silver, larger blade.

Bob. I went and looked at my compressor plug after you asked about 125V. Plug is marked Leviton 5-15 15AMP 125 Volt

OK so plug rating not the actual power

I guess not, I looked at another "aftermarket" replacement and it too was 125V.