I'll tell you what I do when setting score goals, but I'm still new so you might not take away anything from this.
For my score predictions or aims, I too use a ranged extimate for each distance, per dozen, based on whether I have a classification score to hit or simply a pb. at the moment, it's both, but that's bye the bye.
So, for example, in order for me to hit my short national 3rd class score, I'd worked out that beating 60pt dozens @50 and 80 pt dozens @40 would take me past my 403. It's a rough guide, but it's an easy way to get started, so if you need to do better on the shorter distance, you have plenty of room for manouevre. Having these "markers" not only gives me a guide, but I know that after 40, if I'm over 160, I'm doing better than I wanted.
The important part for me is the adjustment after a shoot. I look back at averages for the distance, then reset the markers.
One other thing I do is try and better my performance areas such as consistency, number of misses or outliers (1s,3s,5s), and shot speed.
Hope that gives you an idea, but it sounds like you're way better than someone who needs to do this
