I don't think the numbers to be model designations. As the descriptions seem to be of individual guns Clever had in stock at that time, they are more likely Clever's stock numbers.
As you mentioned Gustav Bittner's design with the locking bites in the dual lumps (other than the Jaeger/Bittiner/Scholberg designs), don't forget to mention the older British designs similar to Bittner's: The George Jeffries of Norwich patent #3442 of 1874 and the Smith,Townsend & Williams #2778 of 1858. Both feature double underlumps with the bites in the lumps.