toilet replacement

I am hoping to replace my current toilet with this salvaged 1930s Kohler toilet. My current toilet is a rear spud flushometer, but the salvaged Kohler toilet is a top spud. The water supply line is 21 ¼” above the floor. The toilet has a height of 15”. Unfortunately, with a top spud toilet, this...

We have an older home from the 1960s, and one of the bathrooms has a wall mounted toiled. The model (Kohler) is super old, huge, heavy, and is slowly leaking at the wall. We need to replace it, and I'm curious whether you can swap a wall mount w/ exterior tank with a floor mounted rear outlet. I...