Hi. I recently visited relatives abroad where plumbing spares and
knowledge are sparse. There is an Armitage Shanks ASA 180 9 litre
lavatory low-level cistern with a faulty flush mechanism. It's aroung
15 years old probably. It says DPE (or perhaps OPE) Maxiflush on it.
It is fitted centrally and raised by a side lever. The washer
underneath is worn and that is apparently allowing the water to leak
into the basin. Water is scarce there so cannot be wasted.

The washer is approx 2-3 mm thick, internal diameter 28 to 30mm and
external diameter 80mm.

Any ideas please on a suitable replacement mechanism or spares?

Thanks- Bill