1) Kaner suggested that the stock was the frame or stool on which a hive was placed and that is formally possible. In some contexts though it seems likely to have referred to a quantity of bees, a swarm.
1561 I will Harrye Rodwell and Agnes Hewet to have a stock of the said bees, Fairburn
1593 Item a bee stocke 4s, South Cave
1668 to my grandchild ... one stock of bees to be given ... for her own use at the end of 3 months next after my decease, Hambleton
1672 tow stoakes of bese, Burn.