I don't think Mike has that piston for sale anymore. He just hasn't upgraded his web site for several years. I tried to buy vintage pistons from Mike at Portland in July, and all he had were the new edition pistons modified to fit the vintage motors.
The piston going in this rebuild [upgrade] was from Kenny Thomas's private collection and I picked it up at Portland this year.
Just a little history, as Kenny is one of the leading Whizzer historians.
Have fun,