Hi there, and welcome. Three speed lightweights like this are my my favorite knock around bike - You'll enjoy it. Have you tried looking under the cover? That looks like a gel saddle cover. Usually added to address a discomfort issue. You may actually have a nicely preserved original seat under there.
By the way, if you haven't already purchased this bike, how much is it? People (including myself) tend to overpay for their first bike when getting into the hobby. If you did already purchase it, keep the number to yourself. It's sunk cost, and once you are sailing down the road with a big smile, it won't matter anyway.