I have been told the Speed Trap is made out Butyrate a.k.a. Cellulose Acetate Butyrate. I don't know if that has been changed. Butyrate is weaker than ABS of the same thickness. Butyrate is easier to mold into very thin-walled items like the Speed Trap. A lot of Speed Traps end up with small dents/dimples from the molding process. Take a look at the belly of your Speed Traps. I know some lure companies will use Butyrate for some models to get a different rattle sound than other lures. It produces more of a deep thud type sound.
I am a fan of the Speed Trap too. It is a great lure. The Metallic Perch color is one on my favorites. Of course, they discontinued that color. I have one that I painted black that works great too.
Mark, I know you have made your own version of the Speed Trap which looks great. I thought you might like to read the 'Tech Sheet'.
Jim
SpeedTrap tech sheet.pdf