We get quite a few round here as the area (Surrey, Hampshire , Berkshire boarders) is swamped with birch. I have had a couple that size off birches round here before and just given them to friends to carve or play with. Found a really large one on a pink flowering horse chestnut at the entrance to the national shooting centre in Bisley....that went to a good friend of mine who was very chuffed to get it.
Southy....if you mean North Camp, Hants....as in the north end of Aldershot then watch out I don't find your burl first! Lol (joking).
As it happend I was out today over at G8 training area near Deepcut and a small birch was on the ground with a 10" burl wrapped round a 3" trunk. As it was on the floor I picked it up and brought it home....it'll go to the same mate
I come across loads of small ones during my work but an hours walk in any of our local wooded areas and you'll find one or two....whether you can/should take them is another matter