Plater's Marks

Can anyone post scans with examples of Carroll Chase's and Stanley Ashbrook's plating notations on the reverse of stamps? I recall an article in one of the journals (probably the American Philatelist or Bureau Specialist--a search of the Chronicle comes up empty) that illustrated the notations of several notable platers, but cannot locate it (if anyone has a citation for this I would appreciate it as well). Many thanks.

I don't have any examples of Ashbrook's notations but here is a decent example of Chase's plating notations

Thank you, sinclair!