I think your idea is very interesting Michael and it certainly is worth a try but I guess I'm a bit skeptical though. I have rebuilt many motors myself, (probably not hundreds though) and I've never run into a brush seating problem. That doesn't say that it doesn't exist. Historically I've found that if the commutator was good the new brushes would contour themselves. I did many Electrolux canister motors like this in fact without a problem. Electrolux made a great motor. You could wear those commutators down to almost a valley and even without turning them a set of new brushes would make them run well again. In fact I have an old cardboard box labeled "National Brush Assortment". This is slightly larger than a cigar box but not as deep with compartments in it. It contains many different sizes of carbon brushes. This was part of a load of stuff I got when I was a kid from a hardware store that was going out of business. It's probably from the 40's or 50's. None of these brushes were contoured and I've used them in almost everything that's walked in here needing brushes over the years without any problems. The motor is presently in my son's house and he's on vacation for the next two weeks so I won't be able to revisit this project until then. But I will post my results after. Thanks everyone for your input. Lenny