I have several of these arca-style plates for sale. They are all in excellent condition. They each come with in a bag with the screw, allen wrench and instructions. The price is $25 shipped & Paypal-ed.
Sorry, I don't have the 2164 plate. While the others do have a long screw slot that allows for some adjustment, I don't know enough about them to know if any would fit the BG-E6.