Walther
Bersa, Berreta
Iver Johnson was the manufacturer.
A week or so
Fegarmy Arms Factory Ltd (Budapest, Hungary)
FIC was an importer, not a manufacturer.
Herter's was an importer, not a manufacturer. No published sn data on what they imported.
Yes, rubbing alcohol can be used to clean a handgun. It is effective for removing dirt, residue, and oils from the gun's surfaces. Make sure to follow all safety guidelines and manufacturer recommendations when cleaning your handgun.
It depends on the brand and model. Check with the manufacturer for an owner's manual.
Internet searches, Blue Book of Gun Values, library, manufacturer of the weapon.
You can find extra cylinders for a Titan Buffalo Scout handgun at gun shops, online firearm retailers, or directly from the manufacturer's website if they offer spare parts for sale.
Normally, you can't with any assuredness. The serial number itself won't normally reveal the manufacturer.