It's all about the barrels. Most embarking on such a project would want a gun that has barrels that are sound and un-cut, free of defects such as pitting and one's that ring like a church bell which signifies that the ribs are not loose--although that could be rectified...it's only money! Because of the investment I also required an ejector gun, but others may prefer an extractor gun.

Here is a pic of the engraving on my nearly completed 20-gauge Sterlingworth Ejector.