[Dixielandjazz] Composer challenge

[Craig I. Johnson]

The Anderson Fake Book lists the Composer of
"I Can't Say" (recorded by The New Orleans Boot Blacks
but released under the name "New Orleans Wanderers" in 1926)
as being Lil Hardin
However, the Red Hot Jazz Site lists both Lil Hardin Armstrong 
and Louis Armstrong as composers. 
Anderson lists Lil Hardin Armstrong as composer of Flat Foot (recorded
and released similarly to the above. same year as well))
Whereas Red Hot Jazz lists again Lil Hardin Armstrong / Louis Armstrong.

Anderson Does NOt contain charts for the following but
they too are on the Boot Blacks/Wanderers  2 records and
are also listed as Lil Hardin Armstrong & Louis Armstrong composers
"Mad Dog", "Mixed Salad".

Can anyone confirm or refute whether Armstrong was in some knows 
way a co-author and that Lil was Armstrong and not Hardin at that time?

Craig