Dave, thank you very much.

Just to verify

Scenario 1. If I have extension 125 and I simply want to replace the phone but keep the extension and programming, I plug the replacement phone in and dial 7 to replace.

Scenario 2. If I have extension 125 and I want to replace the phone, use a different extension and return to factory programming I will dial 3 then the 10 digit number...(on the new phone or the old phone?)

This is good info thanks again, I am going to tool around with my phone today and see if I can get it replaced.