That's not even necessary on this typeface. The number set has the tails 3, 4, 5, 7 and 9 extend downward from the base line a bit, similar to a "g" or a "y" to achieve a fancier look. The "th" is actually on the baseline.
It is. You are correct. “Th” just slightly higher. Weren’t some electric typewriters able to do a modified superscript?