My father was an exchange student in Manchester, UK, from Gdansk in the late 1970's.
Have you made inquiries at Manchester (university) (I assume). There might be a yearbook or photo with his full name.
The same applies for Gdansk.
Someone might have posted a photo or mentioned his name at FriendsReunited. The site does have listings for universities.
You might find that one of your mum's friends can remember something that will help.