Ohio rifles have such a wide variety of styles. To truly appreciate this variety you really need to look at the books "Ohio Gunsmiths and Allied Tradesmen" as was suggested by FALout. Ohio guns have a distinct taste of regionalism: you will find different styles in the northeast by Toledo, different styles in and around Columbus, different flavors by areas that border the Ohio river, different styles yet again on the south west border.
If you want to build a good representative Ohio style rifle the only pre-carve available is the Vincent, however, you could use a Lehman and modify it to create a generic style and call it Ohio. Truly, you need to build from a blank, pay attention to the buttplate shape, the trigger guard shape, shape of inlays, shape of patchbox or capbox if you decide to add that. Other differences can be found in the shape of the cheeckpiece (some guns have a cheeckpiece on both sides) lock shape, the nose of the comb....there are a lot of subtleties between styles and that kinda makes the building of these things fun.
Unfortunately, the available castings for buttplates and guards are pretty poor. Basically, they are too small to accommodate today's triggers and the space between spurs are too small. The solution is to find old originals and put them to use, but again, you will find, thru study, a very wide variety between guard types.....
From what I understand, the Ohio Association of Long Rifles will have a table at the CLA....and if you really want to get a leg up on your build, call the Log Cabin and ask for Tom, he is the president of the OALR, he can set you up with a lot of good options.
Good luck on your build!
