I deleted Check for Possible Duplicate Media Plugin and then reinstalled it. The install went fine. However you need to be patient with the download and install of md5 and luasql library modules. It takes a while to download them. I suspect this is a limitation of winhttp in Wine as I do have a reasonably quick internet connection.
Now for the even better news Check Installed Plugins Against the Store works perfectly. This is the result:
Crossover will be my next tests but I need to get the laptop out for that whereas POM is readily available on my iMac.
Winetricks is not the easiest thing to install, I know I have tried before. Hopefully Crossover will have similar functionality to POM. I will report back in due course.