so I traded a beat up old kirk hammet kh-503 for this bassman ten. its in ok shape cosmetically and has one torn speaker. I checked the insides and all is well. it has mostly cloth covered wires and no mods at all. good thing is no leaky capacitors ect... so I'm just trying to figure the date of this thing out. I love the sound especially with the channels bridged and definitely am not getting rid of this thing anytime soon. but any help on the date would be cool. here are some pics of the transformer # and serial #. it has 2 tube charts. they glued the first one upside down by accident then glued another over it LOL. oh also it has all the original preamp RCA tubes.