The numbers are always between 1 and 4, which denote the quarter of the year it was manufactured. 1 is January to March, 2 is April to June, 3 is July to September and 4 is October to DecemberLooking at one - it's got a D stamped on the plate underside - seller (US) says D4 in the description - is that a specific date in 1958?
Black beauty would finish my vintage adjustable set. Not expecting to ever afford a toggle or a bottom dial Fatboy.I have a Bluetip B1 (1956)
Black Beauty 02 (1969)
Both in pretty good nick. Not getting any love. Happy to sell to a good home. Not looking for a fortune. Pics upon request