on google searching, I came across this set.
e-bay number 122473558952 closed on May 31, 2017
Clark's best screwdriver, mfg. by R.H.Brown, New Haven, CT and on their lable is April 22, 1873
in there description was;
"a patent handle screwdriver as produced by Frank E. Clark, Westville, CT and marketed by R.H.Brown, & Co.
is marked with a patent date of April 22, 1873. we have sold these before and could not locate the patent
it is very likely that date is for a patent issued for a improvement to dental tools. it is for a spring clip
to hold the tools in a handle. patent # 138,150" issued to Charles P. Grout New York, N.Y.
I think that this listing was by M.D.Tools
not seeing your handle, I am not sure if I am on the right track. compare yours with a Clark's.
I had sold a Clark's set a few years ago in a wood box. I do not collect screwdrivers,