Afternoon!
I am by no means an expert on branch mint halves! I have consider branching out (forgive the pun) to collect these little beauties but stopped myself because I need to first complete my London coins first! However, I can answer some points below.
First though, I must admit that I have the fairly easy to come by 1925 and 1926 SA halves. Two recent versions in beautiful condition were sent to PCGS for restoration last month so can update on those if there is interest! So I have already started to not just think outside of London…..
As for the 1897 Sydney, this is what I can see from my books and other brief research:
1. Marsh First Edition (see pic) confirms ‘Not known’. Published in 1982.
2. Marsh Second Edition (see pic) confirms ‘Not known’. Published 2004.
3. Marsh/Hill ‘The Gold Sovereign’ (see pic) confirms three possible versions 503, 503A and 503B (Proof). Published 2021.
So, as is the case with all research combined with societal and technological changes making obtaining and reviewing coins easier - more is being discovered. The 2021 Marsh/Hill is the place to concentrate and first check which coin it is that you have. You may also want to get some high resolution pics taken so someone can count the denticles!!
If you can post pics we can have a look and see whether it’s a 503, 503A or 503B (incidentally, these are just the Marsh references for the coins).
Cheers,
Andrew.