Eric,
Yes I was really excited last night to see that it was from the same maker. It does have a real hand made look and finish to it. Very finely made.
There's nothing under the pin, no other markings. I was wondering about the Vatt under Mutt myself. Sadly I have no understanding of German dialects but you could well be right on either of those. Daddy and mummy is usually replaced by mum and dad over here as you get older.
Feasibly it could simply be a trait of that particular family and not common.
Very pleasing engraving, so well done. Under a loup you can really appreciate the workmanship.
Glenn.