Two million pounds sterling was a horrendous amount of money at the time. Enough to stretch plausibility to the breaking point.
Assuming the money in question came in the form of 18th century British gold coinage, we're talking somewhere in the area of 10 or 15 tonnes of loot. To propose that people would use human power to lower that much gold into a pit over 100 feet deep is. . . optimistic.
OTOH, assuming it was wasn't in the form of precious metals, then by now it's in the form of compost.
Assuming the money in question came in the form of 18th century British gold coinage, we're talking somewhere in the area of 10 or 15 tonnes of loot. To propose that people would use human power to lower that much gold into a pit over 100 feet deep is. . . optimistic.
OTOH, assuming it was wasn't in the form of precious metals, then by now it's in the form of compost.