1) "Enchanted stone golem" in Ivory tower krater used to spoil varnish at 1-7 quantity, but only spoils 1 now. I realize that accord to the drop table on the monster it is indeed correct, but I have spent many hours in IT in the past farming varnish and it was always an amazing spot.
2) "Leto Lizardman Warrior", in the Plains of the lizardmen used to be a good monster to farm Coarse bone power, with the rate 1:5. This morning I killed maybe 50 or so, and got 1 CBP.
Somehow the chances of CBP and quantity of varnish must be bugged.