"Right on the col - the scar to the west has large holes immediately below it." This seems to exactly describe Schachtgruppe 36 as seen from B4. B5 was not relocated in searches in 1990 and 1995. The Austrians thought B5 was the same as Kat. 35, but Waddington notes that the descriptions don't match well and Auer's map shows 35 as SW from 36. However, Wisenthöhle (1623/75) is very close to B4, and if snow levels were high could be a 10m descent to a snow choke (Olly's theory).