Home made horizontal milling machine.

[Toolmaker51]

Very nice build actually a superb build for your at the time stated age. And a great restoration of a machine you actually knew the detailed history of each and every part on the machine.
As far as the usefulness of a horizontal mill goes I used to leave the Rt angle adapter on my J head Bridgeport for months on end until I finally got hold of a Cincinnati #5

I'm thinking, it's more likely the Cinncy#5 got a-holt of you, Frank S. Once you walked by it, the affair was on.
Sure has occurred to me, oft enough. Who are we to resist 10k pounds of iron?
Real horizontals are where it's at for boring. Why?
The part is always supported over the Y axis ways, not the sag beyond saddles of X. The engineering term is called 'Abbe'.