My 2 cents, is it depends. About 6 years ago I purchased off Gunbroker a Parker VH 12 gauge, 30" barrels on a number 2 frame. Most common Parker made. I paid $400 for the gun and it had a severely cracked stock, because someone had drilled a hole in the buttstock (a bad recoil pad was also added) and poured molten lead into it, probably to balance the gun with those long barrels. Over the years the lead expanded or the buttstock contracted (I've heard both) and the stock was split on both sides and there was also a small split at the head of the stock. I knew all of those things going in, but the price was right and it was my first Parker. I got the gun with no idea of restoring it. I simply wanted a shooter that would work for ducks with bismuth. I went on the Parker guncollectors website and asked about getting the work done and someone recommended a fellow located in Ga ( Bill Scwartz I think) who was a good smith who knew Parkers and who could undoubtedly take care of the buttstock issues. Also, less I mention it, the gun was mechanically very sound. Chokes were full and full, screws had never seen a screwdriver and the bores were outstanding. Gun had not one speck of case color (except the watertable and forearm iron and blueing was pretty gone.
Anyway, I contacted the Ga Gunsmith and told him I wanted him to repair the stock because this was a shooter pure and simple and we agreed on a price for that service and off the gun went.
After the gun was received, Bill called me and said this was a prime candidate for restoration and he would be glad to undertake it if I wished. Cost as I recall for the "Whole Enchilada" was $1,000. I decided what the heck, for $800 more then just have the stock repaired, plus a new (repro) Hawkins pad added I could have a pretty nice gun, so I said go for it.
Probably 8 months later I got the gun back and it looked like a new gun. Wasn't perfect, because I could see where the stock repairs had been made, but everything else was super. In fact, it was almost too nice. Thoughts of using it to hunt ducks disappeared and I went the Benelli route instead. The gun sat in the safe for several years unused. After a bit of time I decided that was pretty dumb, as it wasn't a new gun and I'd just go ahead and use it. It became a great gun to use pass shooting doves and it also became my turkey gun when I wanted to do something different then the norm. In fact, I think it will be the only gun I carry with me while turkey hunting this year.
The cherry on top of the Sundae happened last year when I went to Nebraska Turkey hunting and brought the Parker as my backup gun. Without getting into the gory details, I got too close to my Benelli SBE and got bit by the scope mounted on it and blood flew everywhere. Now really scared of the Benelli I pulled out the old Parker and decided to give it a go. Was rewarded the final day with the following at about ten yards:


Now, if I decide to sell that Parker at some point, I won't loose money on it, but I also think its pretty special the way it is. I no longer worry about beating it up, but I am careful, just like I'm careful with my other side by sides. So my answer it if you want to restore it, do it right and get advise from folks who know what they are talking about. Turnbull seems to be the current gold standard, but there are others out there who also do good work. My final thoughts is do what you want its your gun, just have fun doing it.