it is a little less powerful but not by much
50-400 usd
Yes you can. The bore is the same size.
Not in .38 Special. Several manufacturers make handguns in .38 Super, though.
No. Only use what is stamped on the barrel.
No, i asume you dont have see .380 pistol and a revolver 38 spl, the .380 and 38 spl ammo share de same diameter boot no the longer, the 38 is for a 38 special revolver tipe and the .380 is for an automatic pistol tipe some people call 9mm short.
Impossible to say without a more detailed description of the handgun in question.
Library, Blue Book of Gun Values, Standard Firearms Dictionary.
100-400 USD depending on condition.
I'm not real familiar with the 38-40, but based on what I looked up, I'm going to say no. The 38-40 cartridge uses a .40 caliber bullet, which means the chamber in a 38-40 handgun would be too large in diameter to properly/safely hold the .38 special.
Model numbers were not used before @ 1957.
10-10000 USD depending on specifics, history, accessories, engraving, etc..