These old Encyclpedias are generall written by some of the foremost authorities on each subject.
I would suggest the older the better as far as history is concerned. They are far less Politically Correct than most newer ones.
BTW I once got a full set of Britannica in almost new condition for free. They were at a thrift shop and was missing one volume. When I asked for the price, the clerk said I could just have them. The next day I picked up that missing volume for a quarter at goodwill where they had a large number of loose volumns.
I make book cases for them and they look pretty nice in the living room, den, and even bedrooms.
Even with the internet, I think encyclopedias are a very under-rated source of info.