Well, of course you are correct in principle -- given enough time and money, you can certainly replicate the state of technology c. 1986. But that's not the question, unless you are engaging in purely academic musing. The real question is one of cost. The paradox of advances in technology is that building old chips in a new fab is not directly feasible. The recipes (and dimensions) have changed so much that it is impractical to undertake such a task for under, say, 10 million dollars. That's how much the first chip would cost; the rest would be free. But you have to pay for the first one to get the second.
The best option would be to arrange a deal with the few remaining legacy fabs. Many military contracts specify very long term supply guarantees, so there are a few old fabs still in operation, but they are disappearing rapidly. Get your orders in now!