Mosquitoman.
Never heard of that bomb load. The lanc had two mounting points for the "cookie" range of bombs, with two different slips to be used in the airframe to recieve the carriers when winched into position.
the first was for the 2000 and 4000 pound and the second was for the 8000.
The 4000 and 8000 pound bombs were supported between the wing spars in the bomb bay roof due to the inherent strength of the roof there. If you tried to hang a 4000 pound cookie anywhere else you would rip the bomb bay roof apart as it would not support the weight.
There were also significant C.G. issues with trying to get even two into the Lanc.