[slotloco]

Actually Gordon

you probably just solved the mystery.
That may well be the reason Salvatore went with 4-40

Salvatore was a top steel chassis racer - at the same time as Ernie Mossetti or MR Slotcars.
Ernie once told me that Salvatore won his world title using a car Ernie built - I cannot confirm or deny... 

Alan - will be interesting to hear what Giovanni can tell you.