From what I've gathered, I
believe a timeline would look something like this:
Earliest examples: stamped on left side "Tyler's T-Grip Okla City 14", rear of adapter reads "Tyler T-Grip" and size number, 2-piece paper-labeled box
Next examples: added Melvin's name to side and eliminated rear casting reading "Tyler T-Grip", stamped on left side "Melvin Tyler's T-Grip Okla City 14", rear of adapter a size number, 2-piece printed box
Next examples: removed Melvin's name and added 5-digit zip code, stamped on left side "Tyler's T-Grip Okla City 73114", rear of adapter a "T" and size number, 2-piece printed box (possible adoption of powder-coat finish at this time)
Next examples: changed from stamping to etching, left side reads "Tyler's T-Grip Okla City 73114", rear of adapter a "T" and size number, 2-piece printed box
Next examples: same as above, change to 1-piece printed boxes
Next examples: same as above, change to plastic bags
Latest examples: removed marking on side, plastic bags
One might think the Melvin-marked adapters would be the earliest but I have some and they don't have the Tyler name cast into the backside, which I think was probably a feature on the earliest molds. Here is a photo of what I suspect is an example of the earliest version:
Disclaimer: I may be wrong and have some things out of order but, like I said, this is what I've gathered collecting and trading these things for the past year or two. I welcome any corrections.