What is the best starting procedure after a 18 month layup? My C5 has been garaged in an 'AirFlow air bag' but temperatures have been down to -10 degrees C.

Do I change the oil and filter first, or after giving it a run to drag any minute debris/rust into the oil filter before changing? The old oil had only done a few thousand miles and was Mobil 1.

Should I drain the 18 month old fuel from the fuel tanks and, if so, what is the best method?

Is there a way to 'prime' the oil before starting the engine? I know that older models could be primed via the distributor shaft, but what about a C5?

Are there any other precautions/actions to take prior to firing her up?

Any help would be very much appreciated.

Welcome
Drain the oil and change the filter. I'd dump a can of dry gas in the tank. Try and fire it up. If it wont fire then dump the fuel but it should go. As soon as you can add fresh fuel and techtron. Not the most cautious but if it were mine this is what I would do. I am sure there will be different opinions. If you want a world class ceritifed C4-C5 tech to answer..post up at corvettemechanic.com Best of luck

Welcome to the forum.
As mentioned do the oil/filter change. Gas that has been sitting for 18 months most likely has been effected by condensation so either just dump it or try an additive. Next time you anticipate a long storage period it is probably best to just drain the fuel.