Your best bet is to keep an eye out on this website here for any information. The last channel to own the UK TV rights, was Hallmark. You could try contacting them directly, to see if they still have the rights for Seasons 1-4, but in all honesty, it's unlikely now, and you'd have to try and persuade them, or another appropriate UK channel to air the show again.
A great show, ruined by ITV1 when it aired back in the mid-1990's on Saturday teatimes! (I am aware it was also on Sky 1 and Sky 2 - the old BSB Squarial channel, not the new one.)