(Blake Street is a little station on the north side of Birmingham)

When visting London via this route I usually get a day return to
Marylebone on Chiltern, with a zones 1-6 travelcard on the same
ticket. Would this cover me to catch the tube to padington, then the
train to Southall?, then the bus to Southall Broadway

(I have an Oystercard if that is a better option, but as far as I can
see you can't use em on this line)