Nice find
View attachment 1520551 View attachment 1520551
Welcome to the Forum
View attachment 1520552
Your English is excellent.
If you think you will ever want to sell it, then don't open it.
If it gives you pleasure to own something rare, pristine and new in the package, don't open it.
If you think that if you open it, you will fidget with it, maybe carry it a couple of times and then it will sit in a drawer (or wherever) and not be used, then don't open it.
If you want to carry and use it, open it.
If your going to stress over it too much, open it and solve the problem

Its not an uber rare collector piece, at least not here in the USA. Being in the USA, I'd probably do what others are recommending and get another, already opened one, to use. May not be the case where you're at.
Bottom line: Do what will give you the most satisfaction and don't worry about it after the decision is made. If you don't open it now, and it bugs you, you can always change your mind and open it later. Once its opened, its done.