No wonder you did what you did luv2safari!
That is one exquisite piece of kit there - the engraving is superb to say the least!
As it's next custodian you should be justly proud of such a wonderful piece of history.
Speaking of such, it must have an interesting history with a crest on it, if you find out more please post this up.
When you do get a chance I'd suggest a cast of all the chambers & twist rate - as this may point you in certain directions as to paper, brass or plastic hulls; as well as what projectile weigh to use.
As to the 10.5X47R (if you find this correct), can you tell us a bit more about it please?
I'm assuming all loads will be with BP?