Creda now spinning but?

Thanks for brush confirmation: have had machine top & bottom off again, pressed anything vaguely loose, but have also blown in motor. Have switched machine back on, no load, and it's spinning away merrily. Was unable to locate brushes, confirming sadly that i am just an enthusiastic amatuer, but does this still mean brushes are worn and in need of replacement? Or have I inadvertently solved the problem by dislodging dust/other obstacle?