Quoted from Bud:

You are a bold man to buy an old NIB pin without opening it to check out its condition. I have bought 2 old NIB pins and wouldn't have bought them if I weren't able to open it up and check its condition. If the seller is so sure everything is fine and you leave a few hundred dollar deposite before you open it then all should be well. If it checks bad, you lost your deposit and he still has his NiB pin that's never been played. In the end it doesn't matter if it's been opened up as long as it's all there and carefully removed and put back. It's not everyday an old pin that's never been played comes up for sale. That whole "but it's been opened" really only applies to newer pins.