Footnote:
I've just entered values for George VI and almost across the board those prices have increased. It seems his reign has been undervalued and is now catching up. (Mind you, mostly there are only values for EF and UNC - but to compare, Elizabeth II is static.)
Values aren’t everything. Some of us want to handle our coins with care, viewing under different lighting conditions, as nature (or mints) intended, not entombed in scratchable plastic.
I'd say your 1913 is 1+A - the reverse is clearly so, and if you look at GRA:BRITT on the obverse and compare it with the 1915, you'll see there is a bigger space between A:B and the I of BRITT is to a space not a tooth.