b61-407 IVORY TIPPED SCREW ARM PLOW. Ohio Tool Co. No. 105. Solid boxwood version of the No. 105. Several chips on the threads and the ivory tips, unmarked cutter slightly spalled. The toe has the "Columbus" line from the B mark as well as the 105, but no trace of the "Ohio Tool Co." line. Could be worn off but looks like it was deliberately omitted, maybe to allow it to be marked by the retailer. Good 200-400