Farymann K30 Oil Dipstick Rubber Gasket

Hello!  Was wondering if someone might be able to send me a photo of the rubber piece at the top of the oil dipstick and possibly measurements too.  Mine must have loosened up and fell off.  I'm sure it is in the deepest, darkest spot in the bilge!  I looked trying to find it but with no luck.  For now I have a rubber stopper that keeps it plugged but I have to keep the dipstick itself out.

I would greatly appreciate any information anyone might be able to supply about this rubber piece.  Thanks!

V/r,
Scott