Milsurf, what you call the quillion I would call the cross guard. The quillion is what some call the hook and it is rare to find a 1907 version. I probably have somewhere around a dozen 1907 bayonets and all are non hookers. Most if not all have blued metal from the pommel to the cross guard and some are blued about 3/4" past the cross guard onto the blade. Using a strong chemical on a bayonet such as this must be a NO NO. I sometimes soak bayonets, if rusty, in diesel but eye protection must be worn at all times when handling/using diesel.

Why not post some pictures, if able to do so, before starting any restoration work?