I would "guess" a full restoration would be $6000 plus. I see on Doug Turnbull's web site he estimates a full restoration of a VH at $3600 plus, so I would assume you couldn't get the additional engraving and a new stock for any less than $6000. And that may be very conservative.
If you are serious abut restoring it, I might suggest you contact him at
www.turnbullmfg.com and send him these pictures and get his estimate. That would be a good start and you could get other estimates if you think it worth while.
As to what it would be worth after the restoration, I suspect less than the cost to restore it. How much less I don't know. Other here may have better advise or opinions on its value.