[DaveBlake]

...so will revisit those particular artists and make some changes.

Good

Yes, I have tried manually selecting Cdart from the info dialog, but still does not display anything. I also changed the code and tried using $INFO[Player.Art(discart)] as suggested by @scott967, but still nothing. I was about to give up and put on my list of things to fix, but I took a look at Guilouz's Estuary skin Mod, where he has a download button for AB on his info dialog. So added this functionality to my own skin, along with the variable he uses and I can now get Cdart appearing.
However, this does not work in the way I thought it would. If I manually select Cdart from the info dialog after making these changes, still nothing shows, but if I manually select the Cdart from the info dialog, then select the AB download button, it does appear. I probably need to look at it a bit more, as getting Cdart to work using this method with hundreds of albums would be quite a lengthy process I would imagine.

I think you need some help on using AB, sorry I can't help there.

Meanwhile there should be a manual approach that works. I'm not saying that is the solution for hundreds of albums, but I would like to get you to that point just for my own satisfaction.

Which "info dialog" - song or album - did you use to manually select Cdart? In the skin $INFO[Player.Art(discart)] or $INFO[Player.Art(Cdart)] is looking at the art of the song for an art type of "discart" or "Cdart" respectively. Try $INFO[Player.Art(album.cdart)], where via the album info dialog you have an art type for albums called "cdart" and have manually selected an image.

I hope to be able to add the core facility to automatically pick up local art (in an appropriate place and with a sensible name) for any type of art. So maybe just wait a bit.