Hi your dealer doesn't know what he's talking about, your motor has wet sleeves every major from the 1952 first "new" style gas and diesel 220 motor like yours including the Ford 5000 diesel as it was badged in North America for 2 years does . The next generation 6X &Y world wide 1000 series are bored blocks, the gas E27N before your style major was to, the perkins conversion ones had a dry sleeve also.
Chances are your liner seal ring or rings have let go or the block groove is corroded out.
That is very common on those engines, Ive seen quite a few over the years. The odd one has dropped a sleeve or cracked one to, but never seen one go porouse like the later 0000 series blocks do. yes they will blow head gaskets but usually there are other symptoms like it blows water, runs hot, don't run right, or won't start with water hydro locking a cylinder, or burns water when it starts.
If it was mine I'd pull the pan put more water in, and see if you can see where it's leaking out. once the heads off and you maybe find it wasn't that unless you can see something leaking under the rocker cover first, you have a job to get water in and pressure the system if you need to find the leak in the block. If it's one ring leaking you should really pull all the sleeves as the others are probably bad to, then hope you don't find its the blocks corroded real bad. That job can become the end of the tractor or a money pit real quick sadly. Regards Robert