Here's what I like: wakeboard control arms:
I bought three of those five for IIRC $8-10 each. Not tested to destruction yet, but they're very light, stiff and curved.
IDK where to look in Nebraska. Maybe something like Habitat for Humanity. Maybe Goodwill or St. Vinnie's for TV antenna masts, etc.
"Glued and riveted internal lugs" I made that part up. Bicycle frames would have external lugs and brazing.