No...Imperial Scout Headquarters were in London at Rowland House. Later the association moved to BP house at S. Kensington which is now a hostel run on behalf of the Scouts. HQ is now based at Gilwell Park but that has only really happened over the last ten years or so. Check out 'Johnny Walkers Scout pages'. Scout Shops used to be based at Victoria in London - its all online now...times move on!!
Lovely sack - your a lucky thing. I know a few Scouters who would jump at such a boot sale prize (incl. me LOL), well done you've a real piece of history there.
kawasemi