Leaking one-piece wall hung toilet

The house was built in 1980, but some parts seem to be mid seventies
in origin. A label inside the tank of one unit says "Mr. Plumber" and
a model number. I am attaching pics, in case you have any experience
which might shed light on what/where/how. I am striking out. All one
part wall hung units I have found are tankless.
I live in rural suburban Portland, in Colton. My house on the beach
is a vacation rental and as of yesterday, the guest room toilet had
to be turned off to stop water leak. Time to solve this recurring
issue...
Kathy

toilet

It is a Case/Briggs model 3000 wall hung. It is the best toilet ever made because it is not only more sanitary being on the wall, but it will also not overflow if it gets plugged up, saving a big mess, especially if it is on the second floor. ANY good Briggs or plumbing parts store will have the parts you need. They come in kits depending on what needs to be repaired. But they are expensive parts. The complete float valve runs about $200.00. There is no other toilet that will replace it without a major remodeling of the wall.

Thanks hj, I hadn't seen a toilet like that, I was hoping you would get a look at it,
Terry

I removed a floor-mounted version of that a year ago, after 30 years of service. I have to admit, the first time I replaced the fill valve/flush parts I was shocked at the cost. I tore the parts down for scrap and was amazed at how the screws and parts were still in good shape. It was never a great flusher. No other ballcock will fit because of the way it mounts on the china.

I've never seen parts for it anywhere, but ordered mine from a plumbing supplier, Sexauer. A lot of plumbers have access to them.