Good morning Paul,
Thank you for your continued support.
I did go ahead, download the 2004 version and tried installing as per your instructions earlier. This time, however I did a clean boot, and installed without the option to download updates (though I should say that the clean boot was probably not complete as msconfig kept freezing everytime I tried to disable non-Microsoft services and would not shutdown properly). Nevertheless the result was the same and I got the following screen.
Here are the two zip files.
Rollback: https://1drv.ms/u/s!Au3fg5D4gYxajR5KPfBdr3BuRtuJ?e=9PTg6iPanther folder: https://1drv.ms/u/s!Au3fg5D4gYxajR-YLBgJ2A7Olu-G?e=VLKV4p
Meanwhile, I don't know if it is relevant. I tried doing DISM RestoreHealth with and without source options. I used current ISO downloaded from Media Creation Tool as source. In both cases, it returned a source not found error.
Thank you again for your help and hoping that these folders help in fixing this problem as I hate to do a complete reset.