Rear PTO question

A while back I was using my 140. It has the (under 30,000) rear PTO installed. There was nothing being ran by the PTO at the time, when for whatever reason the round shear plate disintegrated.

Closely examining the round shear plate it looked to be possibly made of 1/16" spring steel. Not having anything on hand to fabricate one, I pulled a scrap of 1/8" aluminum sheeting out of my bag O tricks and fabricated a new one. My figuring the use of the shear plate originally being steel, and the added thickness of the aluminum would have near the same shear factor considering it's use. I'm somewhat skeptical even though I have the PTO back together and balanced.

I'm looking for feedback, thoughts and experiences from others who have done what I have?

Thanks
Dom