what is given as F.v. Dreyse 0,70" with serial number 50730 its probably SN 30730
this is clearly the last version of the old double gun model with common shotshell extractor also for 0,70" needle fire cartridge, the system being made more slimmer and the new trigger's

http://www.hermann-historica.de/db2_de/auktion-70.html

0,34" Damengewehr SN 2152
http://egun.de/market/item.php?id=5565986