1864
The G stands very tall, the D is same height as B. The D's initial downstroke runs off the r and so to come back to form the D the writer carries up and across, and then back down to meet that initial downstroke before moving on for the o which then runs into the n which in turn then runs into the capital B which rushes off into the l without going completely back to the base of the B, but clearly it is a capital B. And so just as that B is capitalised, I see the D as capitalised.
I cannot say that the J Gordon Blair's signature is from same hand as Gordon Blair's signature, but I cannot say it is not, so I agree with Sue .... no conclusion, so I am hoping Gordon's signature on Elizabeth's birth cert is available.
Of course, errr .... Jane Novral may have had a male friend attend to register the 1857 birth .....
JM