I played my 1972 JMP 50 Lead 1987 for years and one day I opened the Slant speaker cab to look at the speakers, and I almost dropped when I noticed Jim Marshall signed the inside of the cab in Jan of 1972. The bottom has the kid (Builders) name Rob, and Jim's was there in pencil on the side. This 1972 Model 1987 Lead is an England Build amp and my best sounding 50 watt out of 1/2 dozen. In honor of Jim I show my amp in this thread. Original Mullard tubes, and was the last month for the Red Circuit boards. The Yellow Boards started in Feb of 1972. I put screen grid resistors in the amp. And the greenbacks are the Pulsonic cones 102/3. This amp goes to the grave.