I have used both the Alpha and PEC 250 K pots for the Lar/Mar and the PEC pots were better at lower volumes, they had less artifacts than the Alpha pots. If you are not going for super low volume the Alpha pots are fine but there is a discernible difference between them. That's why George Metropoulos started using the PEC's. After George posted this video I bought one to try it and it was better as described above. I agree with George's findings and comments below.
Metro Amplification comments in Video below:
Demo of a Metropoulos 50 watt with '68 era lead specs, with a PPI MV mod. The volume pot in this amp is a PEC dual type, which costs $29. I feel the cost is justified by the consistent tonal balance, even at very low levels. By comparison, the $0.95 Alpha dual pot is very inconsistent and sounds harsh at low settings.
Hey V2A did you get your Jake E Lee guitar yet?