Help Cartridge too heavy Need to add counterweig

Okay I purchased a cartridge on the recommendation’s of another thread on this board, however I was told that up to an 11 gram Cart. Should be fine, it is not… There is not enough counterweight to hold it at all, the Arm importer is music hall and they are out of the replacement counterweight right now for heavier carts. And that NOBODY will have them but them, and they are not expecting to see any for over a month. So what is my best bet to add some weight? They told me maybe some washers or something but I would like to do something that looks decent and can last without bouncing around or ringing like loose washers. Thanks I appreciate the help, would really like to do it right.

P.S. Yes I have an expensive digital stylus gauge, one of those recommended by stereophile I forget the name, so anyway I can accuratly set once we get some weight on it.