[rotorwrench]

Neither water or ethylene glycol are lubricants so keep that in mind when finding the dip stick reads way over full when it wasn't that way last time it was checked. I always treated a model A like a tractor. Check the fluid levels before operating it and catch little problems before they turn into big ones.

Water or water coolant mix is a lot heavier then the oil so it will separate quickly and go to the bottom of the pan. Water will mix with ethylene glycol but it won't mix with oil.

The OPs vehicle in question may have been run a bit too low on coolant for a bit too long. Cast iron likes to crack if it gets too hot. It's killed many an old Ford block for sure. Freezing is still the most common killer though.