I don't know if this will help of not, but there is a recall on the Focus to replace the fuel pump if there are any symptoms that could be caused by a bad fuel pump. If you could figure out who to ask, maybe you could find someone that was willing to let you have the old sock filter from one of those. You might try starting with the parts guy. He knows which technicians are doing those recalls. I'm sure that all those old pumps are just getting scrapped.
