Originally Posted by Anorak
Good hardware stores usually have motor brushes in the area with all the drawers of hardware.
This. Bring one of the old ones with you as sometimes the pigtails have slight differences and you'll have 3 identical brushes in a drawer with different spring attachments. Also, sometimes they come in different lengths so measure the brush holder before you go. As mentioned you can sand them down but if you ever have had to actually do it you'll find it is not as simple as it sounds.