IMHO, if that piece is messed up just buy the whole EVOD unit or 3. I don't know your budget but I would rather have a bunch of spare parts/o rings than have to worry about that 1 piece.
This is coming from a guy who is only a month in and has 3 EVODS, 3 Pro tanks, and 4 iClears.
if you were close I would hook you up as I look at my desk right now and count 5 EVOD style bases.