A couple of weeks ago someone (Jack?) enquired about replacement screw
caps for the water tank and sink external drains. I said that I had
found an aftermarket drain tube that screws onto the sink drain plug - the
threads are just plain "garden hose" threads. The water tank drain plug is
a different matter. I've tried as many caps (from the lab) as I could
find, and the one that comes closest, but doesn't really work, is a cap
from a 50ml Falcon tube (mo-bi people know). I'll continue my search for a
cheap substitute.

Alistair