Welcome to the boards Ross!
I`m from the UK too and am similarly fascinated by all the American types of lights, they are so much different to UK lights. I first discovered the fasinating world of foreign and antique lights about this time last year and havn`t looked back since! Bubble lights amazed me when I first saw them! They did make them over here in the 50s, a handful of companies made 12-light sets including Pifco though that is about all I know and have never seen UK bubble lights before myself. They obviously weren`t very popular- wonder why?
Where to find lights? Well I have got all my vintage sets- mostly American but quite a few UK/European ones too- from Ebay,
http://ebay.co.uk. Search for "christmas lights", "xmas lights", etc- they don`t show up too often but can be found if you look hard enough- so long as I havn`t seen them first
.
Otherwise, if (unlike me- agrophobia
) you like travelling round looking for bargains, try antique/secodhand/junk shops and car boot sales- you`ll probably find quite a few 12-bulb sets there in varying conditions. I wouldn`t pay more than about ?10 for a boxed set. Maybe double if it`s in near-perfect condition wit a full complement of original bulbs. Bare strings often go for under ?5. There are very few UK light collectors here, and in the US light collectors tend to favour US types, so demand, and hence values, for UK lights is quite low
Well I hope this helps. Look forward to seeing you round here again in the future! Happy collecting!