I made those comments in your other posts.
Here's my reasons.
I've restored a lot of vintage bicycles. Clear coating over an original paint bike with a nice rusty patina lowers the value.
If you use gloss, it looks like crap. It gives it a shiny lacquered look over rust, chips, and missing paint, brightens up the old paint to an unnatural state, and ends up looking like a "faux-tina" paint job.
Matte clear looks a little better, but still messes it up. You almost always have noticeable bubbles, drips, etc.
It's only original once. It earned that patina, and clear coating it ruins it.
It's not that hard to clean and revive the original paint. You have to clean it anyway to paint it, so you're almost there to save the original paint.
Your bike is a classic. It's not a dime a dozen 70's Puch. Keep it that way.
Clear coating it is mostly just going to protect it from more rust. But if you're taking care of the bike and not just leaving it outside to rot, it's not going to rust anymore anyway.
That's all just my opinion. I've seen a lot of old bikes, motorcycles, and cars that have been clear coated, and they always looked better to me before.
Bottom line, is it's your bike, you can do what you want.