Many thanks everybody. I will take the advice on the liner and just
redo the whole shebang.

Any comments on the pump/filter question? I think the biggest
constraint here is space. Small lot in the city and my wife has
staked out a lot of the square footage for the garden!

I would like to keep koi in this small pond if possible (getting
conflicting advice) so I'd like as much filtration/aeration etc as
possible. I don't mind spending for a compact new filter & pump, or
building a do-it-myself model. I just need to figure out the most
space-efficient design, that can ideally be buried. I posted a
drawing of possible plans he http://koiphen.com/forums/showthread.php?t=63835

Any way to get photos onto rec.ponds?

--Rob