Hey good effort! Good set of new pictures. As you say 1.04 is a bit interesting - the 'snail varnish'
looks a bit like its been rasped away all around the hole though other parts of the shell have peeled off also so tricky to tell if its a sign of the entry technique or just weathering. The other shells don't have it quite as pronounced. Is that why you pointed out 1.04?
If you want an expert opinion I'd suggest maybe contacting someone at the natural history museum. I wouldn't want to encourage everyone to bombard them with questions about nature puzzles - they're busy folk - but I have found them really helpful when I've been stuck on difficult ID's in the past and the folk that work on the less cute furry 'n cuddly creatures generally seem pleased that someone should take an interest in their subject. There are some mollusc folk in this list:
Staff directory - Natural History Museum
and email address is usually
x.surname@nhm.ac.uk i think (where x is first name initial). Otherwise the BBC Wildlife questions and answers might help but could take a while to get a reply.
Hope we're all put out of our suspense soon!
Happy zonitidae searching,
PS snail shells are good to eat for strengthening growing bones - your kids should be eating them!