So I bought two Perlick 525SS's from Beverage Factory and bought shanks from Brewmasters Warehouse. The diagram for the Perlick http://www.perlick.com/store/webcatalog2.php?catno=1§no=1&grpno=3 shows an O ring seat (item 3 on the diagram) and a coupling gasket (item 4). There is a ring...