yes. If they are available to the public which I believe all records in the LOC are (except active administration records or records deemed top secret).
I'm not sure what the status of these records are but I can't imagine that publication records from 30 years ago are either secret or relevent to the current administration.
Now, my experience with the LOC is very limited so maybe someone with more experience can add to this?
If there are bound copies of the magazines, I'm guessing they are like the books - anyone can walk in the door, request and receive them, then read them onsite. I spent a day there years ago reading some out of print books. I must have shown or given them some ID, but don't actually remember it. You have to be more special than a regular citizen to actually REMOVE materials, but anyone can read stuff.