pressure control release valve

hey guys. i have a leak coming from my rear brake pressure control release valve. i can only find 1 on the entire web and that is from famous four and its almost £40.

Famous Four - Part Information for FF001971

any ideas where i might find one cheaper apart from local breakers? It is also known as the rear brake pressure regulating valve if this is of any help.

Cheers Guys

I'm sure I gotta second hand one in me spares stash, if you wanna PM your address (and a nekkid photo) I'll post it out to you.

Mine had a leak, I stripped it down and gave it a good clean it's fine now.