Glad to hear your patience and training is paying off RSVP - Fireworks are one of those sounds that you can't normally help your dog with until the time comes around again, so the recording idea sounds great.
Luckily, our hound isn't too bothered about them, just snoozes, but we took him to very noisy places as a pup to get him used to bangs and crashes (airports/ steam railway stations/ markets and walks in fields when there were farmers shooting nearby) so I think that may have helped with the firework bangs.
The cats however..... good grief! they are petrified even though I've been shutting them inside from 6.30pm each night. Must pop out and get a feliway - Can you get Feliway type plug-ins for dogs too? Might this help also RSVP? Just a thought.
Anyway, thanks for sharing that, I will look into the recordings and see if they work on cats too....