Thanks!  I have both M1903 and M1903A3 front sight bands.  Will try the aluminum woodruff key fabrication route for a 1903 band.  Did you hone the inside of the band to allow it to slip fit on the barrel? For future forum reference I will try to post a picture of the existing barrel flat.  The band I removed did not have a woodruff key installed but it did look like the interior had been polished or reamed to fit on the barrel as the depth of the key slot on the band was reduced.

Did you have to adjust the front sight blade to regulate the rear sight POA to POI or did yours have a carbine rear sight?

Mark