Brad,
Thanks for the photo. I wonder if the '47.2 is different than the 48-54? The two bolts on the lower pan on my '47 are occupied by a lower grill bracket. The upper bolt holes are on the radiator support bracket, but I don't see any sign of the support rods or evidence of them ever being there.
I'll check with some other '47 3100 owners and see if they have the support rods.