A copyright conundrum

This is a photograph of a rubbing from a carving on the front of what was my father's writing desk. He bought it in Malacca in about 1960, so say 51 years ago.
The carving was presumably done from someone's drawing that the wood carver copied. I've done a rubbing from it that I've photographed.

How many copyright infringements have I made....? It may be none if copyright expired after 50 years of course.

Whether there are any or not I love the desk. Unfortunately it's cracked down one side due to central heating, but still a nice piece of furniture.