What could AJ mean? And should I get the Pendant fixed?

by Jasmin delp
(New Jersey)

My grandma gave me a necklace she bought around world war 2 from a czechian woman in germany. It looks like its gold and its like a watch pendant. There is Aj engraved on the side of it and i would like to know if that means anything. and also the pendant doesn't close anymore and i dont know if i should get it fixed or not.