WHAT COLOR SHOULD MY TOW TABS BE?

[PxTx]

I thought this is interesting. Here is a TB3 which is numerically the lowest part number NMW lists. Basically they have the TB3 for 56-62 Corvette, then the next is TB9 for 1967/8 Camaro, then UTB12 for the Universal and back to TB13 for 68 GTO.

I would love to know which tab NMW made 1st and when. I've read some of the speculation on the net. Not sure I agree.

The final finish on the edges of the TB3 do seem to be slightly different, with rounded corners of bolt tabs and such. I wonder if later TB3 look any different? I know there are ealry and late design TB30's.

TB3 is my dad's and the sticker is an eBay repop.