YC-


Worth it or not is subjective.
A proper restoration will be expensive - likely much more than you have into the gun.
You'll never see the restoration money again by way of resale value, and unless the very best effort and resource is put into the project you'll very likely end up decreasing the value substantially in the process.
There is little you can do to *increase* the value, and frankly the best thing you can do for the value is to get it running.
Still that's not going to make it much more valuable to anyone who'd want to buy it (and run it or not) anyway.

Where a gun like this shines is in the hands of someone who will appreciate it for what it is, who is enthusiastic about the period of development of the breech-loading cartridge high-grade sporting gun - and who will be able to enjoy the subtle design and construction features of a nice Brit sporting gun.
No doubt it handles and balances very nicely, no doubt it'd serve you for decades on game in the field and as a fine work of craft and art in your parlour.



Cheers
Tinker