Need info on presure reducing valve o-rings 944S2 cylinder head

[Makis]

Removed my pressure reducing valve (944 107 139 00) from my 944S2 cylinder head to check if OK and now I want to replace the 2 o-rings as suggested by the workshop manual. I checked the PET but they don't specify any part number, they only supply the part number for the valve.

Anybody know if there is an equivalent part number I can use instead? I measured it and it looks like is something like 13.5mmx1mm and green in worn condiition.

So far I researched and it looks I may be able to use the ring (999 707 078 40) used in the 8V head which is 12mmx1.5mm.