I can get more pictures later when I get home, it's mostly an extremely British number of proof stamps, I don't recall anything standing out to me as a date but I may have missed it.
There is no serial number on the cylinder I can see BUT it was milled for .45 acp (Sadly) and I am not sure if it would have been in that sliver that was shaved off.
Also, it may be hard to see in the photo but as I was looking it over it became apparent to me that the sideplate on the side shown in the picture has at some point been sanded down and reblued with the rest of the pistol left in it's original finish. Strangely, later after that someone else then (rather poorly) scratched ANZAC into it.
I have absolutely no idea where this came from before I got it years ago as a spur of the moment gunshop purchase so I have no background on it.