I shall move this to the SOS section where you will be able to get lots of advise from our members.
Good luck in finding Tiggz. Its such a horrible feeling isnt it

My Cedar ran away once (well actually I think he was spooked by something and went to hide). I couldnt find him for 5 days... horrible horrible feeling. The people here were so supportive and offered such amazing advise.
I agree with the above advise. How far is the old home from the new home? Go back there, speak to the new owners, put up flyers wherever you can and drop some in the neighbours letterboxes (or even better, talk to as many as you can so they can keep an eye out).