@old man -
I contacted Graingers about getting the old fomula. I ordered a case of the old 3M 77 at $6.00 per 16.5 oz can! They list both the new and the old formula in their catolog. The formula you want is 3M id. #62-4437-4930-4.
I just looked at the online Grainger catalog and in their hardcopy catalog #395. Neither shows the original formula. The online 3M catalog shows the stuff you bought but is listed as obsolete (in the 16 oz packaging). They do show it current as the "original" in 24oz cans which does not show in the Grainger catalogs.
You must have gotten lucky and found some of the old stock still in inventory somewhere.