Ensigns are great old boats. There is a fairly sizable fleet of them at my club that race as 1 design. Huge cockpit for a boat that size.
In sail away shape it might be worth a few thousand to somebody. That said, you would not make any money restoring this one with an eye towards selling at a profit - ain't gonna' happen.
Restore it only if you like/love the boat and want to save it from the dumpster.
Sounds to me as though you could do this though. You would learn some new skills along the way like working with epoxy. A good place to start learning about epoxy/fiberglass is: WEST SYSTEM | Use Guides
You'd have a few years to be on the lookout for a 5 - 8 HP outboard motor for it. Assume it has a motor mount on the transom?
You will definitely spend some money on new spars, rigging & sails and there will definitely be some headaches as well as triumphs along the way.
Good luck however you choose to proceed.