In reply to Simon Caldwell:
I agree. Club's don't offer formal instruction, because that becomes hedged around with liabilities and qualifications, as well as taking up people's time when they want to be climbing themselves. This statement is just a disclaimer. However most clubs are happy to show novices 'the ropes', although they will encourage them to go on a formal course. Most climbing walls offer short courses, and if it is just a matter of refreshing your out-of-date knowledge rather than learning from scratch then that may be all you need. Of course, if you want more there are lots of courses available.
I would think any club will welcome new and enthusiastic members, especially one with previous experience. Presumably you picked up some alpine skills from your guided trip, so it will just be a matter of developing those, and don't be afraid to ask other club members for advice - between them they probably have a wealth of experience they will be glad to share.
Don't be put off - contact the club and go along. I'm sure you'll be made welcome. But if you find that club isn't for you for any reason, try another - they are all different and I'm sure you will find one to suit you.