Nothing.
early 1900's
Value of any gun is based on make, model, and condition. There were dozens of different models of the H&R top break revolvers in .38 S&W- could be $50 or $250.
in the early 1900's many small machine shops turned out small break open revolvers in different calibers. Also, larger machine shops also made the break open revolvers and put the name of the firearm dealer on the weapon......so, many different dealers sold their revolvers under their brand name even though the revolvers were made in mass by large machine shops............................
You will have to cal Colt to find out. SN data published stops @ 1985
the Hopkins and Allen break open revolvers are black powder shooters. they date back to the late 1890's up to early 1900's. I believe your pat. date should read 1885, not 1985 ????? you should not fire modern ammo out of these old timers. They were made in 22cal. 32 cal and 38 S&W caliber. 38 S&W cal. is NOT a 38 special, but rather a shorter case.
$ 150
The cases were originally loaded with higher pressure, higher velocity loads for the 38 Special revolvers. Not to be used in older revolvers chambered for the .38 Special cartridge.
Impossible to answer without knowing who made it
No published sn data
Yes, depending on the model and condition, You did not hit the lottery, but there is some collector interest in these out-of-manufacture revolvers. We can't tell you how much without some info from you.
Revolvers do not have safetys