start out with positioning tractor on a known flat level surface.
check/adjust PSI - all 4 tires, even pressure - side to side.
take all measurements from underside of blades at cutting edge.
make SURE that blade(s) have not been installed upside down.
perform deck leveling per owner's manual instruction.
disregard any measure to the deck shell itself.
post back with details if still trouble.

I've done all that at least 3 times including checking the length of the front links. The blades themselves are even. It's the mower deck itself that is off, by one inch AFTER, I loosened the nut attached to the arm to lower the deck and tightened the nut on the opposite side to raise the deck. Net difference is an inch. I'm dumbfounded.

Did I accidentally do something to the deck in driving up onto the ramps ? I can't see anything. The mower cuts fine, except one side cuts lower than the other.
Your help is much appreciated.
Thanks,
John

not sure if we are on the "same page"...
When leveling your deck, ALL measurements/adjustments are taken/made from the underside of the BLADE surfaces just adjacent to their cutting edges.... let the rest of the deck shell go where it will will go.
If you have that deck leveled both front to back and side to side FROM THE BLADES there is no way one blade can cut lower than the other unless the deck itself has been severely twisted - or one of the the blade spindles has been severely damaged - or if one blade has been incorrectly assembled..
To test for that condition ( bent blade), take a leveling measure, rotate the blade 180 degrees so you can repeat the measure off the other leg of the same blade - they should be close to the same. A straight edge laid across the two mounted blades from the underside will tell you if there is a "step" between the two blades.
Lastly, have you done the steps suggested earlier ( level surface, tire psi, etc. and are you following the manual instructions in sequence as written ( sorry, gotta ask - no cyrstal ball here)?