Lois, I have some information that might be useful to you since I too am researching some Lefflers in Ohio. I think you're looking in the wrong county for info about Solomon Leffler. Your Solomon and Daniel Leffler were listed in Marion Township, Hocking County, OH in the 1840 census.
In the 1850 Fed. Census, Solomon Leffler is still there (born abt. 1808). There is also a Christena Lefler (born abt. 1813) listed in this census, a John P. Lefler (b. abt. 1779) lots of Weidners and Cull's. Actually, I have a complete print out of everyone living in the Hocking Co. OH area that was born in Germany. This is where I found all these names mentioned above.
In a copy of the"Ohio Eagle, Lancaster, OH 1814-1840 Genealogical Abstracts' ( which can be found at the Fairfield Co. District Library in Lancaster, OH) I found a couple of interesting notations I had copied down about Lefflers of the area, which would be Fairfield Co., OH:
My wife, Christina Ruff, has left my bed and board without any just cause or provocation. I therefore warn all persons from trusting her on my account. Jacob Ruff , Feb. 9, 1837.
page 149: Married on the 13th of Jan. 1839, by Rev. C. Speilman, Mr. Daniel Leffler to Christina Ruff, of this county. (Same Christina as above. She is part of the Ruff family I'm researching)
page 179: All having legal and just claim to the estate of Peter Leffler Jr., late of Rushcreek Township.John Leffler, Administrator
page 84: Sale of land for taxes for 1831- Martin Leffler.
Page 116: Married on Oct 29, 1837 by Rev. C. Speilman, Mr. Mathias Bairly to Miss Nancy Leffler, of this county.
page 105: MarriedOct. 11, 1833 by Rev. M. Wagenhals, Mr. Solomon Leffler to Miss Christine Weidner of this county.
Page 117: Sale of land for taxes: Peter Leffler, Rushcreek, 80 acres.
I have a folder for Leffler/Loeffler research and found a piece of paper with Solomon Leffler, b. 1798 PA, d. 1826 OH on it. Maybe he could be the father of your Solomon?
My interests in the Leffler/Loefflers of that area are in trying to find siblings or parents of a Rebecca Leffler/Loeffler, born about 1809-1810 in Ohio, that married a Frederick Ruff, born 1812, Dobel, Wurttemburg Germany, d. 1897 Fairfield Co., OH. Having no luck at all there. Hope some of this helps firstname.lastname@example.org