SPEA Toilet Cistern - Outlet Valve

[Barns]

Here is a challenge. I am looking for an outlet valve for a SPEA toilet cistern. I know that SPEA is a European toilet but a search on Google draws a complete blank. I think that I did find it years ago but the company may no longer exist under that name. It may have folded or it may have been taken over and/or changed its name.

Anyway, the outlet valve is rubber and measures 60mm outside diameter, 27mm inside diameter. It is approximately 5mm thick and has a central rebate on one side approx imately 2.5mm thick and 39mm in diameter. My plumber here in Melbourne tells me that it is not available in Australia, but may be available in Europe.

Any assistance on this would be greatly appreciated.