I have added a scratch brush tool post to my blog focusing on using a scratch brush with fiberglass bristles to remove lettering on freight cars.  Photos and writeup are on my blog I started to share photos and writeup of modeling projects on my Minneapolis & Northland Railroad Company.  If you would like to take a look please do at the following:

http://mnrailroadcab100.blogspot.com/

Lester Breuer