[oldeboo]

In the 1960 ACC, F92 is mentioned as being from Aro Milk which tells me that the stock should have a wax or polyethylene finish depending on date if they came from a milk carton. I wouldn't think F92 has anything to do with the series being discussed as it seems to be an issue from not long before 1960 and F92-2 and F92-3 probably during the 1960s.

In later updates there are:
F92-2 ROBIN HOOD TRADING CARDS, PD, anon, in code, Aro Milk, 3-1/4 X 2-3/4
F92-3 Famous Americans (#17 seen) PD, 1966, anon, 3-1/4 X 2-1/4, Aro Robin Hood Milk


The last F278 designation I'm seeing on updates is F278-48. The F278-49 designation is another Post Famous Americans series that looks significantly different and appears to be a premium. The F278-49 offer expired on 12/31/1935. I'm not sure when the F278-49 and F278-50 designations were introduced. I'm not seeing anything from after F278-50.

My best guess would be it's a type 2 sort of thing that just wasn't mentioned or catalogued. It seems that different sized boxes is probably the answer. F278-50-2? F278-51? Just F278-50 in different sizes? It's whatever one wants to call it I guess, at least from what I'm seeing.

It's hard to draw complete conclusions from the ACC since the work didn't continue. It's sort of like reading an encyclopedia from 1960 and saying that is the complete story on a particular subject.