I'm not sure that I would dismiss the bayonet idea. I've seen a few but not to many of the swords like not2sharp has posted and non of them have had the T shaped spine like on the one posted by Manolo. I have an unidentified bayonet with a T spine and a bronze grip and guard that has a blade almost identical to the one in the first post. I will take pictures and measurements and post them tomorrow as it is getting late and I hear bed calling me.
Robert