Haig Dimple Pinch
 

Today I was given an old bottle of Haig Dimple Pinch (a US import). It is boxed and unopened and was probably bought back in the 70's or early 80's. It is 15 year old Scotch Whisky, 43% proof, 75 cl.
I looked up what they sell for and I can buy another for £180 from a whisky dealer. Obviously it is not worth that selling. My problem is, do I keep it or do I open it. I have never bought whiskies to keep. Whisky is for drinking, not looking at (I once bought a special bottling of Ardbeg, only to find I had a rare signed bottle. I still opened and drank it).
Oh what a quandary!

As long as it got stored properly and didn't oxidized, might still be good to drink.

I'd go ahead and drink it.

It's not maturing any more in the bottle. Keeping it longer, you're just risking degradation.

The issue was more do I drink it or sell it. I didn't want to open it to drink and find it was "off", when I could have sold it! I have received advice from a whisky expert who says, provided it was kept cool and out of sunlight it would keep "indefinitely.
It was kept just like that, so here's hoping.
Old corks can deteriorate, but this has a screw top so will be fine.
I will be drinking it very soon.