Everytime I dig a blade with my fisher 1266x the signal is somewhat trashy but not fully trashy and those are the signals i dug, i been using the 1266x for years and know right away if its a nail,big piece of iron or wire. Awesome finds, your right you gotta dig up the big iron in a cw area.
I use a Fisher1265 X and a CZ 7 . They both share their love for iron . I'm guessing , not an expert on CW , is that blade an 1849 Ames riflemans knife