Hi Guys.I have an early S/N R-4C (17717) and finally have some bucks to do some of the Sherwood mods. I need some advice on which mods are "must haves" and which ones are "nice to haves". I'm mostly a CW op, but some SSB also. What is your recommended "priority list" for the Sherwoods? I assume the audio amp and product detectors are at the top??? 73, Darrell W4CX