Not worth the time and effort. Transducer have a limited life.....besides, you have no idea if it's works for not. Buy cheap unit on E-bay only to find out the transducer is bad..... you can buy a new unit for less than $100.The xducer is not as bad as the pics make it out to be. Most of what can be seen is actually just dirt.
I was hoping I might be able to get a cheap HU on ebay or something. Not worth the time/money?