The Motor Shield from SB Components needs the 'import' of "Pi Motor" but after several lengthy searches I am still unable to find it. Any suggestions please.
The library source code is linked to from the SB Components website, where there is a link:
This leads you to this GitHub repository, which contains
PiMotor.py, which would seem to be the library you want.
Simply download that repository, extract the files to the directory of your script, and then running
import PiMotor should work as expected in your script. If you're not familiar with why that will work, you might find the "Import System" documentation valuable to read.