Hiya mate, welcome to the forums (if you havn't already been welcomed

)
I studied at liverpool uni for 3 years so I got to know the place quite well and I used to check out worlds apart, forbiddon planet and toys r us alot and all i can say is that that takara galvatron has been there a long time
I know a few places to find TF's in Liverpool but not Chester. hope your TF search goes well. some general shops that sell TF's are:
Worlds Apart
Forbiddon Planet
Toys r us (TRU)
Argos
Home bargains (found energon unicron there for £10 in 2006)
TK Max
The Entertainer
Wilkinsons
Lewis's (in Liverpool)
Woolworths
for Commemorative editions all I can say is try your local comic/movie merchandise stores and TRU. so far i've seen what you've said, prowl, tracks, red alert, skywarp and Soundwave.
Also you'll find more fellow brits in this thread
ODB 262 pages, most full of piratey goodness. Enjoy your stay