Quality of Bases, Forts and Airports

On the main country purchasing screen you can see the quality of your Defensive Forts and Bases. If you go to the Inspect Army menu the qualities are blanked out.
Does purchasing these with higher quality increase their defensive value?

Yes, it works with forts, weapons, and ammo.

I bought higher quality ammunition, used less and saved a bundle, while doing more damage.

However, higher qualities don't improve your war situation index or sitrep, but the do improve the defensive value quite a bit.