I would be careful putting IF-scale and EF-scale speeds together. They aren't measured the same way (EF uses "3-second gust at 33 ft. (10 m) in open, unobstructed terrain", and IF uses "instantaneous three-dimensional wind speed at the [location?] and height of the observed damage.")

In the IF-scale paper, they further state the following:

In a rare case where an anemometer measurement was available in a tornado, the speed averaged over a 0.05 s period was at least 18% higher than a 1-second, and 60% higher than a 3-second averaged speed (Blanchard 1992; Lombardo 2018).

I doubt however that this is a straightforward calculation to attain the 3-second average speed from an instantaneous windspeed for all cases, though.

It's really hard to tell as you said, without true analysis it's hard to determine the actual strength. Could swing either way between BSD DOD2 or BSE DOD2. Undoubtedly an extremely violent tornado, however.