Help identifying this No.4 Mk.2 proof mark
So I picked up a No.4 Mk.2 this weekend, and I took the lower handguard off to look at the markings tonight, and I found this:
https://mail.google.com/mail/u/0/?ui...&sz=w1896-h835
So I am guessing the "F53" is the manufacturer (Fazakerly), and the year it was made (1953), but what is the proof mark above it? I went through my Skennerton book and I could not find a damned thing about it. You guys have any idea?
I also have no date as to what the original year of manufacture was, but it was FTR'd in 1956. Serial is A81XX.
I appreciate the help.