My Garmin Etrex 30 has given me years of excellent service. Sadly, the rubberised buttons are beginning to fail, and the device is difficult to start (or stop) I have been unable to find a replacement case, and I am looking at alternative to purchasing a new unit. If I can get a new Etrex 10 at an economical price, can I swap the electronics with those from my Etrex 30?