(27 Aug 2017, 2:49 pm)Dan wrote I think the simple answer is "lots".
There's quite a few buses kicking around in the fleet which should have long since been withdrawn (having been replaced by other cascaded buses earlier in the year), but were retained over the summer for these contracts, and that's before you take into consideration any buses being withdrawn after the loss of Miscellaneous Works contracts.
Hopefully all of the ex London B7 Presidents will be withdrawn when all of the contracts end. (Like Metro etc)