Am sending my timing cover to AMR for their anti wet sump modification and no longer need this valve.
It is distributed by RGM Motors of Great Britain and called "automatic non return valve". It fits
3/8" ID hose. These are available on fleabay from several sources in the $65-$80 per unit range.
This one is lightly used and only the very best oil has passed through it. Absolutely no wet sumping
with it installed along with normal oil pressure and flow. Yours for only $38 shipping to USA included.
PM if interested.