To anyone looking for the gasket seal. (rubber ring). I just bought a slipjoint washer at Lowes. In the plumbing supply. (package of 2 for around 2 dollars.) The packages says inlet 1 1/2 inches, outlet 1 1/2. You can get them at Ace hardware too. These fit perfectly, and are cheap. The one's at Lowes are black instead of red, but work the same.

Try ebay
and
www.thegourmetdepotco.com