Thank you all for your great comments.
I had a lot of fun rediscovering my old toys - when I was a kid everything revolved around Star Wars for me and it has been a real joy to see them all again. I didn't open a single item though; took a picture, boxed 'em and moved on as I had such a lot to go through and no real space to do it in. I don't think my parents binned a single thing and combined with the junk that I've accumulated in the last 20 years since I moved out, there was just so much stuff.
Anyway, loft is now half as full as it was and I plan to go back through everything in the coming weeks. From a collectors point of view I wouldn't know if I have any unusual items or interesting variants (other than those highlighted by others in this thread), but if I stumble across anything that looks interesting I'll post more pics!
Cheers!