Found \Program Files\PothosSDR\bin\lms7suite_wfm
This folder was empty.
Copied files from downloaded and unpacked 'lms7suite_wfm.gz'* archive into the folder.
Section 3.6, step 3 now works as expected.
Now failing at section 3.7. Reporting my OpenGL version as being v1.
That will be another story...
*Edge downloaded the archive file with a '.gz' extension.
Had to rename it to '.tgz' so that WinZip could unpack it correctly.