I own a Nichols &amp; Shepard 25-85.  I would like to know the year(s) this tractor was made.  I know the entire history of the tractor and the granddaughter to the original person who bought it believes it's before 1910.  She thinks her grandfather bought it in 1906.  I also don't have a serial number/plate for it.  Did Nichols &amp; Shepard put serial numbers on their tractors?  I contacted the Indiana Center for History and they told me there is no known knowledge of serial numbers or that the information has been permanently distroyed.  Can anyone tell me about my serial number delimma?