Hello Carsten, thank you so much, yes I think you may be correct, the dates I have for them on there birth certificates certainly compare, so it is a really good clue. I didn't look past the fact that they must have died in Germany, because why would mum and dad leave them behind? They were only 4 & 5 yrs of age.
Thanks again, I really appreciate you efforts and you have given me a great clue.

kind regards Steve