Hmm. I'll have to dig a bit deeper then. It's entirely possible I have my boolean logic inverted! Ignore for now and I'll post an update as soon as I've figured out why it's provided the list it did.
I think it may be more complex than that. It is certainly possible that I've forgotten to upgrade one of my smokers, but (a) the count seems to include everything so is too large and (b - more importantly) this doesn't give me the guide I need to find out which of them I have missed.
Cheers, Barbie.
-Nigel