Anything is restorable if you throw enough time and money at it.
But wanting to restore this one is not unlike buying a hot rod car and wanting to restore back into an original Ford T sedan.
It can be done.
To restore this fine sporting rifle back to mil spec, to replace everything that has been modified with standard parts, will need a replacement barrel, receiver, fore stock, butt stock, hand guards, metal bands and hardware. All still available. You can easily find them on line. $$$.
You might be be able to use your bolt, current trigger guard (maybe) and trigger group, mag, the rear sight assembly and probably the butt stock bolt.
So you will in effect, be restoring your bolt back into an original service rifle. And the bolt will be non matching!
Churchill are still in the business of rifle makers. They did sporterised versions of surplus Lee Enfields in the 1970s and are sought after by hunters. They are good quality and well put together by professional rifle makers. Better quality than a lot of them out there.
Although not particularly valuable, they can command a price. This one would not last long without a buyer if it was put up for sale. It looks to be a nice one!