Tony,
I also have a FMTC144HDK 14.4V Hammer Drill, (bought from B&Q prior to 2004) and also looking for new batteries.
Have you had any luck procuring any new batteries?
I have a phone number for Performance Tools (bought prior to 2004). I've tried it today but nobody there today, (Good Friday). 01302 721921.
Brian
April 2012