I think the main reason a lot of the older players used such a heavy bat was down to the extremely high price for an English willow bat in India and the typical shape had masses of wood in it to reduce breakages. The Indian Pro's I played with and against always quoted this as the reason they all used 3lb's as Sachin started with, he drops down an ounce every couple of years due to long term injuries.
He has them at 2.13 dead with a small round handle and single grip.