Walther PPK Old Style Safety Catch

Looking for an "old style" safety catch for a Walther PPK 7.65. Has the square firing pin. The part I am looking for is 36a on Numrich and can be found by following this link: http://www.e-gunparts.com/productschem.asp?chrMasterModel=2100zPPK

Anyone with one to sell or information on where to pick one up would be appreciate. Thank you.