i bought my engine from them 20 years ago. they were straight up on what it was, and the price was right for what it was. when it arrived, it was missing the vac drive, I know, who cares now days, but needed it then. called them and they shipped one out the next day.
the thing to remember is they deal in salvage, so they have no idea the history of items. I do not know what they do on avionics. i would assume they at least bench check them, but ask before you buy.
bob burns