I've seen these for sale at Gamblers General Store, along with other lammers.
Some of them are shown on their website page (below), but they have still more in their case up front in the store.

Some lammers: "KILL", "1/2 KILL", etc. used in poker. Others on the Craps table. Still others for certain Asian games.

I don't know the use of "ENVY" and "PLUG" lammers.

http://www.gamblersgeneralstore.com/pages/lammers_and_markers/69.php?list=0