Any(home) heating and cooling experts? Thermostat install problem.

RE your stat diagram......I would jumper Rc and Rh, and hook the blue wire to the Y terminal.

X2!

You know when the guy wired that and used a blue wire he was thinking to himself how funny it would be in the future. Although if it's a really old system then I'm not sure if they still had the same color code. Anyways enjoy your AC! Not that you will need it for a while up there.