Transmission to smallblock support brackets pictures needed

I would think they are there to take stress off the bell housing. But agreed , once they come off they rarely get put back on.
Agreed, they help attach the trans to the motor and take stress off of the case. I always use them. Just had mine powder coated and reinstalled. I think those brackets are very important. IMHO
They are what's attaching the engine to the bell housing below the crank centerline.