Back in the 70s the Post Office refused to hire my mate's brother because he was a member of the communist party

Of course you are not alone with complaining about Royal Mail, downunder we also complain about Australia Post.
E.G. I have just received 2 parcels from the UK (Kernow and YouChoos) both of which at 8am this morning the tracking system of both RM and AP were telling me were still in the UK awaiting a flight to Aus. They must have the fastest planes available to get them from London to my front door in 4hrs.
As for being refused a job because of being a communist, think about it, we were in the midst of the cold war. No way was anyone going to get a job in an organisation which could involve touching national secrets.