OK, that did it. I phoned Cranes and the chap I spoke to (Pete) was great. I had talked to stacks of dealers about stock/prices/when to come and try them out and got everything ranging from ther brush-off, lies about recent price rises and spec changes, through to helpful folk calling me back with a full list. Cranes were the friendliest - even including the promise of a back room and the amp of my chioce for as long as I needed.. I was also interested to try the 2003 Standards against a '57 Reissue Goldtop they had secondhand...
So, after about 3 hours, trying them with a Cornford Harlequin and a Flextone III, and getting their excellent tech to set both up 'just so' (although they wouldn't change the gauge on the '57 for me unless I had already decided to buy it) I finally went with the '57 Reissue.
I have had a childish yearning for a Les Paul since, well, childhood and now here it is, all gold with a very slightly tatty brown Gibson case...

. I paid £1600 - I have no idea if that is good, bad or indifferent. It's £100 less than they were asking initially - bottom line is I have a big grin. Anyway, I can heartily recommend Cranes - a fantastic place too - worth a visit if you are down that way - just don't go on the day Wales are playing at home like I did.