SB Cam Thrust Plate P5249637 no longer made? Only tensioner now?

No spec that I know of. I do not even think that tensioner plate is thinner. Just looks that way in the pic.
That could well be.. I don't have one to measure... maybe someone does. But if the trhust is from the back, it doesn't matter once things are running. I just thought that a .156" plate would be danged hard to bend a tight 90 degrees as shown and not break.

So, perhaps it would not be all that hard to make a thrust plate, once the right steel is selected.