Hi Dex. How about a photo?
It seems that you've done your research. I would guess that not ALL puffy shades were reverse painted, because rarely did a manufacturer do anything all in the same way.
It's not unusual that your shade would be unmarked. In fact, it's unusual to find either bases or shades marked in any way, so it's especially nice that your base is marked. Your shade could easily be an unmarked Pairpoint.
Anyway, about that photo....