Awesome, thanks guys! One trip to the shed with an allen key later and I can now confirm that I do indeed have a seat post that looks like that (thanks ColonelJLloyd) and a single clamp at the top of it (well done Yo Spliff!). It's so much easier when you know what you're actually looking for! Dangly bits notwithstanding, I will therefore be getting a B67 S for my birthday!

Slowtostart: Yes, I love the Lovely Bicycle blog! Actually, I've been very slowly following her guide to what she would do with $500 for almost a year: http://lovelybike.blogspot.co.uk/201...intage-vs.html

I didn't have £500, so I picked up my bike for £150 and have been upgrading it whenever I can afford to change something. It's been lovely gradually upgrading my bike as I've got more into cycling, and feeling each benefit as I install it. Can't wait to add a new saddle!