Fortunately, there are lots of collectors in the UK. You can sign up to the UKVAC mailing list to post arcade related questions, but 'chatting' on the list is generally frowned upon (as with most forum lists). You're better off talking on IRC which can be accessed through the UKVAC homepage. Also, you can register your collection for others to view (and to view others!) at VAPS - The Video Arcade Preservation Society.
Lastly, the RGVAC newsgroup, which is a US based newsgroup and is a source of REAL knowledge! The only problem with this is that they don't tend to answer very basic questions and do use a lot of technical language when they answer.