Impossible to answer without knowing the model and who made it.
We need a make of derringer.
No way to answer without a make and model. Serial numbers aren't unique to one firearm.
Yes, many have been made in 38 Special
I was told by a gun collector that a five digit number on an imported derringer is not a serial number- it is a lot number ( a serial number should be at least 6 digits) what about the proof markings on the gun? can this identify the company or date or just the country of origin?
No public database- sorry.
Only what someone is willing to pay !
100 or so
No way to answer without a serial number and complete description
You don't provide a serial number.
Impossible to answer without more information.
No published sn data
$50-$75