That it had to be swiped is normal seeing that it is a foreign issued card, that will still happen a lot today, what is not normal is that no one checked your signature/identity as it's the only protection that the cardholder and the retailler has against fraud.
How did the PO Visa cards work then I wonder especially being pre paid to tell them when you had no more credit on there if there wasn't some form of chip to store the information

Could have been on the magnetic strip ?