Going through my combos today, I noticed four distinct patterns, in conventional and "scoop" versions.
From the bottom up:
Conventional raised-panel with raised lettering (so far, all I have are Parkerized, so possibly WWII production)
Conventional raised panel with stamped lettering ("Barcaloy" on all my specimens)
Scoop raised panel with stamped lettering
Scoop with large raised panel (I call these "Billboard" pattern)
The Billboard pattern seems to be the latest production. Some specimens have etched markings instead of stamped ones. Many of these are marked "Wardmaster" so probably supplied to Montgomery Ward. These etched markings are very prone to wearing away. Another small difference is that some of those with stamped markings do not have the high polish on the Billboard plating seen on the later production.
I have not mentioned the Powr-Kraft versions or the Crescent ones. I need to look closer at them, but memory tells me the PK Scoop ones exist in both versions.
