i've found a lot with the transverse bracing, some look like bar welded to the tines, others are obviously twisted wire, and even brass spearheads.the thin tines were springy. i am guessing that if they were too springy for the local eel sizes, the bracing would help. i couldn't find any explanations. brass wire makes sense as it is more corrosion resistant. an antiue with rusty tines should probably not have them flexed, as the rust may crack off and the tine fails/breaks. you can see the ones with t he wider guiding prongs have dull points thgat protect the thinner tines from damage on rocks, the ones with thin tines may be designbed for sandy or muddy bottoms.
a variety of heads with this transverse bracing: