580C serial number plate gone ?

I just purchased a 580C and the serial number plate is not there. I've read alot of post and have looked in the cab to the right of the seat (everywhere). To the right and left of the steering column. I have a number off the cab, a serial number off the hoe ( 5377297 ) and an engine data decal # 321-2940, a casting number on the block A-136813.

I would really like to know what year it is so I can start the restiration. After reading hours of these post i am confident I am in the right place.

Any help would be greatly appreciated.

580C serial number plate gone ?