Acually you have it backwards it is a 1975 Jim Dandy. The 1612's and Jim Dandys are basicly the same but the JD's still has a 14hp engine like your 1614 PK.
Yes those are the right tires and I argee they look small in that pic. This one is a little better.
I thought that once they went to the smaller ladder frame they where called 1612s, I guess not! Thanks for letting me know!