Malcolm, I took the class in 1957 or 58 and if I even still have my class notes, they're filed away somewhere. I can't recall now who Prof. Fowler was quoting, but I believe it was someone like Evelyn Kendrick Wells, William J. Entwistle, or MacEdward Leach. Whoever it might have been was venturing an opinion, and Prof. Fowler allowed as how it sounded reasonable to him. I don't know of an instance of "weapon knife" in a ballad text, but I don't find that particularly significant.

In the absence of definitive evidence one way or the other, any opinion is, of course, just that—only a matter of speculation. I merely put it forth as a reasonable possibility. I am not emotionally invested in the matter, and should definitive evidence eventually be found, then that would solve the question. In the Grand Scheme of the Cosmos, I am content to accept a measure of uncertainty in many things.

On the matter of "brown sword," the Bibliomania web site came up with this:—

Brown Bill A kind of halbert used by English foot-soldiers before muskets were employed. We find in the mediæval ballads the expressions, "brown brand," "brown sword," "brown blade," etc. Sometimes the word rusty is substituted for brown, as in Chaucer: "And in his side he had a rousty blade"; which, being the god Mars, cannot mean a bad one. Keeping the weapons bright is a modern fashion; our forefathers preferred the honour of blood stains. Some say thè weapons were varnished with a brown varnish to prevent rust, and some affirm that one Brown was a famous maker of these instruments, and that Brown Bill is a phrase similar to Armstrong gun and Colt's revolver. (See above.)

"So, with a band of bowmen and of pikes,
Brown bills and targetiers."
Marlowe: Edward II. (1622.)

Brown also means shining (Dutch, brun ), hence, "My bonnie brown sword," "brown as glass," etc., so that a "brown bill" might refer to the shining steel, and "brown Bess" to the bright barrel.

Another source said:—

'Metal free' or 'metal clear' refers to the difference between naturally occurring free iron and iron refined from ore ('metal brown') - or to the iron derived from different ores. Pyrites, hematite and another ironstone ore require different extraction processes and there were very rare occurrences of free iron. The results of working these ores 500 years ago were not unlike the differences between cast iron, wrought iron and common steel now.

Good swords were very expensive. They did not rust, but went dark and stayed sharp.

Don Firth