Davis Industries of Chino CA did, however, they closed in 1998.
No known published data
We need more information to identify the model. Colt's original single-shot derringers were in .41 caliber, not .22. They did make small single-shot derringers in the 1960's in .22 cal, but they did not have the markings you describe. www.countrygunsmith.net
There is a dealer I know that is knowledgeable about these Omega Derringers. You can contact him at 804-271-0003 and he will tell you.
AFAIK, no.
No
yes a 50 cal.
Based on proofhouse.com, second model derringers in .41 cal with serial numbers 1-9000 were made between 1870 & 1890.
Given the right circumstances and shot placement, any of them
Any .177 cal pellet can be shot from you air rifle. However you will find that some brands are much better than others.
how much is a 22 cal single shot rife by w.h davenport worth made in 1891
Wee Wee!
Ruger did not make firearms in 1934