Dwarves and Mordor

[Morsul the Dark]

Mordor a name so fowl when it is said a a nearby window breaks instantly. and yet it can not have always been so afterall numenorians lived there once...but here's the thing when it was fair and wonderful...were dwarves in the mountains?

I mean Moria and the lonely mountain can not be the only two places dwarves live right? could they have once dwelled in Mordor's mountains?

and if so was one of these ancient Mines Gandalf's secret way of getting into mordor(this particular question was raised by the thread "if they still had Gandalf"