and the Nilfisk GD10 backpack vacuum cleaner exhaust filter grill on the lower dark grey motor part. 

It's under here where the exhaust filter pad is found see SKU   These readily become black and unsightly from the carbon brushes in the motor.

At the moment, standard postage is capped at a maximum of $30 within Australia, so maximise the saving on postage and buy something in the related parts below!