I just can't understand how anyone would go through the time and effort to modify a trap and then use sub-standard materials!

Rob, Yes, the 3/16th flat material will work too, but I think you've OVER DONE the job.

I've used about everything I could get ahold of to laminate many different traps. Some of my first ones were laminated using 1/8th x 1/2-inch flat stock. They turned-out very well but way too much work/welding (I did that too at first). Then the #9 wire was used and it works just fine and is a lot easier to form, weld and is also a lot cheaper than other materials. The wire is a lot lighter, keeping the jaw-weight down and not hindering the quickness of the jaws with the added weight of heavier material.

It's just not necessary to weld the complete jaw/steel parts together. The jaws get very hot from that and could cause some weakening of the steel.

SPOT WELDING the added pieces is more than enough to hold them in-place. A spot weld on one end, bend the wire around the jaw, tack-in at the center and then on down to the other end of the wire and tack it in place. File/grind down the sharp ends and you're done. K.I.S.S.

Unless you're looking to really increase the strength of the jaws on your traps, the lighter #9 wire will increase the holding area of the jaws when put-on properly.

Depending on the strength of your springs, that's another area you might consider moving up to a #2 spring. Weak springs are not made any better/stronger by laminating the jaws!