I've decided I'm going to pass on it...
It was a hard call between machine-lust and pragmatism, but I spent the weekend rearanging and organizing my shop, and I just don't have the spare room for a machine I won't get much use out of... Hole boring would be very handy, but the limited travel of the horizontal mill wouldn't really help me very much. Plus, I'm sure a machine that old would have wear and issues, just like my 1890's lathe.
It's just not practical, and I have to accept that...