I believe the brushroll in the first picture is a 'Tripple Brush Cleaner - for deep down cleaning' l from a DA001 and features the yellow end caps.
My DA001 has the same brushroll and being original is very worn but I dont use the DA001 so I cant comment on its effectiveness. Somewhere there is an original advertising page from a catalogue which explains the Tripple brush (im sure of it).
DC01, DC02, DC03, DC04, DC05, DC07 + USA DC07, DC11, DC15, DC16, DC17, DC18, DC24, DC25, DC26, DC27, DC41, CYCLON !!