Just managed to get another Vero4K and wanted to match it up with the other RPis and Vero running 18.9 (to share the SQL DB) - this is my simple solution by the way, I expect things have moved on since I last queried SQL DB versioning across different devices.
So, is there a repository knocking about anywhere with older images? I’m sure there must be somewhere and my searching is drawing a blank.
Thank you.
Superb. Thank you.
Now my only issue is finding the right one 
The one I have running perfectly on my other Vero4K seems to indicate:
“Open Source Media Center 2020.11-1”
Without wanting to be spoon fed the exact image file…I’m aware that’s exactly what I’m asking for.
The images are usually posted a few days after the OTA updates hit the mirrors and seem to be named by the date when they are posted, not the version.
It looks like there was a bugfix image in December 2020.