I have a massey ferguson tractor that I believe is a 1974 MF 20 Industrial. I have had some people tell me it is something different. What I do know is that our family owned it at one time. We sold it but I have since bought it back. The previous owner gave me a shop manual and a parts book for a 20c. The tractor was originally painted yellow. He painted it red and grey. The serial tag that was attached to the left had side of the dash is gone. There is a serial tag that was on the loader frame. I will have to check that when I get back to my shop. The tractor has a perkins diesel engine. I think it originally came with a backhoe and loader. Still has the loader on it. Backhoe was sold a long time ago. The only number i could find stamped is located on top of the transfer case behind the left driver side seat. That number is 553 543 f91 fd 116. I am not sure if that is the serial number and the assembly number. I am going to try to post some pictures of the tractor.