Frame ID - badged as Allin, but is it?

Vintage bike enthusiasts, a little help please. I bought this frame in a job lot from a chap on the forum. It is badged as Allin, Nervex lugs, built for 27". I would really like to find out a bit more about it, particularly whether or not it is actually an Allin. If it is, I'd like to know when it was built and what components is was likely to have rocked so that I can undertake a sympathetic refurbishment. If it's not, what is it?

The only info I have found online is this article: http://www.classiclightweights.co.uk/builders/allin.html. In it, it says: "Frame numbering was sequential starting with 500 (1946?) through to 2401, the last recorded number dated as 18/6/1981 in the surviving frame building notebook" and "All frame numbers were stamped on the left side rear drop out." My frame is numbered 2640 and is stamped on the bb shell, though I haven't taken any paint off the dropouts to see if there's one there, too.

The dropouts are unlike anything I have seen before so this might be a clue for someone more knowledgable. There is also a number stamped under the word Nervex on the bb shell - 58c64cD22(2)E38. Is this the lugset number?

Pictures here: http://www.flickr.com/photos/timmy2wheels/sets/72157622731285243/

Any and all help appreciated!

well it looks quite a rarity haven't ever seen nervex bottom bracket shell before. nervex were used by raleigh on their high end bikes thus i would hazard a guess the frame is actually british
until you get the frame number from the rear drop you'll never know ! check out bobob's posts about his allin he re furbed one recently it will give you an idea as far as the dropouts are concerned you should be able to compare them from his photo's

i have a stan butler special in very poor repair as my polo bike it rides very nicely, great strong 531 tubing, i do have the frame number on the rear drop out though and head badge and scruffy paint job showing it is an allin

Thanks, Dicki, and also Hilary for the PM. Hilary is pretty sure it's not an Allin. From the further sleuthing I did last night it could well be a Harry Quinn. Frame number is consistent, lugs look right. There is no Q directly before the frame number but what looks like a Q close by on the bb.