7-ups were late 90 IIRC... Later there was a triple white conv. white ponies, next there was the redish/orange white ponies conv. , and then the yellow with chrome ponies..
7 ups have a colored section of the dash, that I believe you can only get if you have that car.
And yes, those two tubes would be the heater core. Common issue on mustangs, most people just disconnect it, to save the aggrivation of trying to replace them.
But seven thousand, it better be really nice...