Wow - that's a winner because that output gives the comments. Many thanks!

If the 2927 has an import function I'll try making a test output of some dummy data. The newer router is due to be delivered tomorrow.

You can import a bind list into a 2927

I hope so. Mine will only arrive later today but on Page 157 of the User's Guide I see both "Backup IP Bind List" and also "Upload from File" on the Bind IP to MAC screen.

Yup it worked.

With the Telnet command of "IP bindmac show" to download the list from my 2920 and then some simple find-and-replace editing plus slapping an "End of file!!! on at the end before restoring it to my new 2927, it was a breeze.

Again, many thanks @hornbyp