Pin size of the top link on the tractor side is 3/4" and, as you stated, 1" on the implement side. Seems to be pretty standard for this size tractor as my 50 year old JD 2020 has the same size pins on the top link. Lift arms pins are the normal CAT II 1 1/8". Guess this keeps you installing the top link in the same direction all the time.
I have the same deal on my MT352 which is a Cat II 3pt hitch. I use cat I implements so use the top link as is and use bushings on the hitch arms. If you have cat II implements then you need a bushing for the top link. I keep several extra in the cab. I loose them frequently - forget they are there when taking off implements,
They use CAT 1 on the tractor side and CAT 2 on the implement side. So your top link should be 3/4" for the tractor side pin and 1" at the implement side. Sounds like the factory may have put the wrong top link on but the dealership should be able to fix that pretty easy.