Model Identification Help: Which Mossberg 500 Do I Have?

I’ve had this 500A now for 25 years. My dad let me skip school and we went and picked it off the used rack in a rundown gun shop. Still my favorite gun in the collection to this day.

However, I’ve tried now for a couple years to figure out which 500 it is. I’ve tried the normal Google route but have found mixed answers. It’s a standard field model with 28” barrel but has a gold trigger and factory engraved scrolling on both sides of the receiver. Gold trigger shows me it’s a pigeon grade, but the engraving is throwing me off. Serial number is P172xxx. Any thoughts?