I looked up Xmas Chocolates just to know what they look like.
One place that had Chocolate Coins it was Kosher! That means they are giving ‘Chanukah Gelt’ as a Xmas present not the other way around. “Chanukah Gelt” dates back before “J” was born. Presents OTOH as you mentioned a ‘century’ ago. That is not comparable.
Besides Who ever said Xmas chocolate was OK?
It is definitely NOT OK!
‘How long something is done’ does not make it a good/kosher minhag. It’s the origin, Who started it and Why that matter.
There is such a thing as a Minhag Ta’us.