I have been looking for over a year for a specific valve for my KWC colt python revolver. No success.
I checked again the KWC website to see if I could be lucky this time (to get a reply from them to order a spare part) and saw a little canadian flag. I clicked and was forwarded to their canadian distributor for parts and some airguns.
http://novafrancaairguns.weebly.com/
That guy replied within an hour that he would have a quote for me today and I received the quote early this morning. Very fast and efficient little company.
I will finally be able to use my revolver again (ordered 4 valves just to be sure at 4$ each).
Hope this might help other people in need of parts.