Scott does not give a concise definition
of what is 'a' and what is 'c'... any
help to clarify this would be appreciated...
By the way they state the two, it (appears)
(maybe) a=imperf horizontally top or bottom
and perf'd between, whereas they specifically
state c='imperf between'
Trying to guess at (either) is a bit nebulous,
most especially-given there also exists a third
type (albeit possibly classified as an EFO) with
the imperf between the frames, with a row of ghost
perfs notably across the top of the head of the
bust in the lower stamp...
(see next image in my followup with ghost perfs)
