Mike,
I saw the proof date late last night. I pulled my 1968 Garcia Beretta catalog this morning. The gun is a GR-2. The 424 series did not have the rib extension.
Here is the list of proof dates:
Bobp,
If you are working off American catalogs, then perhaps you are correct about the dating. However, Beretta does not release all models in all markets at the same time. Please look at my above post from a 1972 Italian sporting goods catalog. Today Beretta has a sxs slug gun in Europe that they refuse to bring into the US.
Pete
