Item Description Photos
 Heater Blockoff Plate Believe it or not, back in 1956 -- you could order a car to *not* have a heater.  This is the blockoff plate kit for your 1956 Buick. 
 Silencer Oil Bath Air Cleaner Century, Super and Roadmaster series with the 322 cubic inch engine had an oil bath air cleaner that had a large "silencer" (or snorkel as some call it).  Here is an example of an original untouched one.  The color should be underhood black, and you can buy a reproduction of the orance AC decal that you see on the silencer.  There is a small mount bracket that supports the silencer from the bottom and attaches to the top of the thermostat housing, which is shown in the last picture. 

 Trico Washer Pump    cam-o-matic windshield wipers with coordinator had this Trico Washer Pump installed to squirt washer fluid from the cabin by pumping/pushing the button on the wiper switch.  You can buy a reproduction of the lid, the sticker and I believe the glass jar -- but not the coordinator / pump nor the bracket that is used to attach to the firewall.