It has FM! All I ever come across is AM radios, kind of a surprise. You could put a switch in at the top of the volume control and select between the radio or an external input. You could feed a guitar pedal at this point and it should work just fine for guitar. It would have the 6T8 triode gain stage going to the 6C4 splitter, to the 6V6's. All the cathode resistors are not bypassed so a little lower in gain and cleaner than we are used to. Just need to hit it with a little more signal from the volume control.