Royal Navy gun telescope Ross

[NavalMark]

Hello Gentlemen,

here i have a very impressive telescope for a naval gun. On the pics you can see the makers mark Ross, serial number and some advices to its former place : Bi-Turret left. Anyone any informations from what period and what sort of gun this belongs ? Destroyer, cruiser .........

I could buy this nice piece of history and ask me what i should spend total with the wooden box ?

Thanks for your informations and advices,

Best regards

Navalmark

[NavalMark]

...the makers mark...

[NavalMark]

....more of the mark ....

[NavalMark]

...the tag on the storage box:

[NavalMark]

..and the last one ....