Thanks to the generosity of Ryan (HistoricalDNACollector), I now have a #500! I wanted to share here my reasons for calling it a #500:
1. Color -- It has a distinct color that certainly could be "Deep Rose"
2. Overall Look -- It has almost a "re-engraved" appearance with bolder lines and markings in the hair, face, and lower design.
3. Bold Button -- This seems to be one of the most consistent traits of Type Ia (#500) vs I (#499): The button border is heavy.
4. Toga Rope Outline -- It is intact and distinct. Although it does not have the classic "uniform thickness lines" throughout the rope outline, I have seen others like this on trusted auction sites like Siegel Auctions that are certified #500.
5. Partial Type III Line -- In the curve of the right ribbon there is a faint partial impression where a 2nd line would be if this were a Type III stamp
Here is a previous discussion thread about Type Ia vs Type I characteristics:
https://goscf.com/t/46191



Also, for the perfin collectors out there, I've been told the perfin here represents Western Union Telegraph. Does anyone have any more information about it? Or an explanation for the extra hole below the "W" (a single mark control perfin?)??? Thanks!