Does the model of air compressor matter??
I think 80 had that same one.
In the later years, it was replaced by the one in the hard plastic case that you commonly see. These are still available at the dealer (at least they were a year or so ago).
By concours, I assume you mean your local PCA type events. Most of those events have a "Wash and Shine" category where they just judge the interior and exterior of the car. Trunk, engine, and underside are not included. Since they don't look in the trunk, not having the pump wouldn't matter.
If you go into a higher category where they check the trunk, you'll generally need the pump. They usually check the tools as part of the trunk inspection. But I would highly doubt that it would matter if it were the later style pump.
Our pca region here in Orange County had a pretty active concours scene when I did it (mid-90s). Even out here, there was no deduction for non-originality in local events. I was always surprised by that. If you covered the seats, you'd get points off. If you left aftermarket matts on top of the originals, you'd get points off. But if you simply spraypainted hard to clean parts, you'd not get any points off! You also wouldn't get points off for aftermarket seats, radios, or generally any other equipment. It was only if you had aftermarket stuff covering things that you'd get a deduct.

