I agree with Miner09. Serial numbers 23149 to 24090. All had a Pacer adjustable front end. They had a gusset welded to the bracket going from the front end back to the center of the tractor for additional strength. The spindles are also a little larger and longer than a MH Pony.
I have send several red Ponies that have faded out to a gray color. I do not know if it was the primer they used or the paint just went gray!! That too makes for more confusion.
The serial number and the front end are the two best methods to determine if they are MH or Ferguson.