It's not really going t be any help but the filters I use are 501721298 Crosland Oil Filter. I guess I just got luck the first time i ordered.
Crosland filters are rubbish. ECP bought the Crosland name from the administrators when Crosland went bust, and now just put the name onto whatever parts they can source most cheaply.
I'd suggest folks avoid these and buy a reputable brand instead; I've always found Mann to be pretty good.