It does seem a bit of an impossible task but here are my thoughts that may help you.
I live in a ship building area.
At my local Historical Society there are a couple of old blokes (and I say that in the nicest possible way) that have salt in their veins or are descended from the likes of shipwrights, captains etc.
They come out with the most unbelieveable details of some of the old ships. They have built models of them in their younger days and have copies of their drawing plans etc.
They are a wealth of information.
They can tell you details like the men/boys of today can tell you who has won every final and what the score was.
Your Historical Society, especially if sea orientated should have some info about the Victory and maybe the details you are looking for. They may even be able to put you on to someone who has looked into it over the years.
You can ring up or go into your main city library and ask for the relevant department and they or you should be able to look up old volumes to look for the details.
Then there is the Maritime Society who may be able to steer you in the right direct.