Here is a scan of the two versions I have of the Milton Bradley Royals card.
As can be seen, the right side has the right text (RA1) for both the 3 roll and the 6 roll in both black and red, so the red number has the base for those.
The right text for the 2 roll and 9 roll are in red for both these variations, so the 1 does not have a base.
Which card is from which year?
Scan_20250203.jpg