Font in I, II, III, IV, etc.

High Times  Suggested by donshottype 
Anavio Condensed  Suggested by donshottype 
Manygo Serif  Suggested by donshottype 

Roman numerals like these are included in High Times.
You would have to customize for _IIII_.

You can use the capital letters from a font based on the Roman letters inscribed in the Trajan column, such as Trajan and squeeze them together.
Some Roman inscription fonts are already condensed, such as Anavio Condensed.
Squeeze them closer together for a closer match

Manygo Serif is almost an exact match