That is correct. Good eye.
Based on the pics, I would guess the tiller is an H70.
The mower deck is a H44 or H46. If the middle cutting blade is shorter than the end blades it is a H46. If they are all the same it's a H44.
H46 is a 48" wide cut. The H44 is a 44" wide cut.
The serial number was usually on the deck under the depth control adjustment lever in that little pocket. Yours appears to have fallen off.
So the H is a match for the year of your tractor.