[Johnson] Johnson 154-2-5 variable capacitor

[Steve]

I have a Johnson 154-2-5 variable capacitor. Looked on the Cardwell web 
site and the closest I could come was a 154-2-1.

Anyone have specifics on the 154-2-5? Peak withstanding voltage, max and 
min capacitance, air gap?

Thanks.

Steve K8JQ