The mystery is finally resolved...
Originally posted by berg417448:
I was reading "Adolf Galland-The Authorised Biography" by David Baker. In the notes at the end of Chapter 13 I read the following:
"Just weeks earlier the Bf-109E-7 had begun reaching the Stafflen, although the variant would not see service with JG26 before early November. The E-7 was essentially equivalent to the DB601N poweredE-4/N but with fuselage shackles for either a 300 litre (66 gal) fuel tank or 330 kg (550 lb) of bombs. The light metal tanks were a great improvement on the compressed wood pulp type, but they did cut performance, and pilots jettisoned them if combat threatened."
Now I have no idea whether they really existed or were really used but when someone reads it in Adolf Galland's biography I can see why they might believe in them.
Thanks berg417448: