If the length of the broadhead of the middle arrow is 3" then that arrow is very close to 27.75" BOP.
Suspect that most of the bottom arrows fletching has been lost over the years but if one just looks at the style of the rest os shaft it is very simialr to the arrow Hill used in taking a bobcat in the Florida Everglades in 1928, page 81 of Hunting the Hard Way. Of course, in this picture we can not see what the broadhead looks like but in 1928 it defintely was long before the Hill broadheads.
If that is the case, then both the bottom arrows could be HH's because they are the same length. But then again back in 1928 Howard may not have been so precise with is arrow lengths.