Orange ? bag
Walter - I won one of those on Ebay recently; it's a US version, which must be similar to the British one, except for having Reg. U.S. Pat Office written on the bag.
It's not quite a ?, since the ? is reversed, there's no dot in it plus the curved part overlaps slightly. I believe that it's for model 725. The model 700 had a similar bag but the curved part of the line was below the writing. I have one of these too but not in very good nick; I'll see if I can find it later.
Stephen