No.My question is, can I use the old tank on the new bowl?
The old Glenwall was a five gallon gravity tank and bowl.
The new Glenwall is a 1.6 gallon pressure assist tank and bowl.
Even if you could mount the tank, what happens when you plug the bowl and overfill it by a few gallons.
Just pick up a new Glenwall, and allow time in case you need to do some bowl and tank swapping until you get it right.