Yes, the 522980 and 522985 Silaflex graphite rods were first offered in 1976. While they looked similar to your rod, the 522 series had a split reelseat with a cork insert. The rod blanks are very slender - typical of early graphite. The 522980 is listed as only 2.5 oz in weight.
The 1980 catalog scan below shows a graphite rod with the same styling as yours. The three fly rods models are discussed in the last paragraph, but no model numbers were given. In the same catalog, the Browning boron rods were listed ahead of the graphite models. The only fly reels listed in that catalog were Mitchells, the 754 and 758 single action reels and two automatics.
From your rod photos, the 622 series were a bit less slender than the earlier 522 series. Maybe Browning had too many broken 522 series graphite rods returned for service? The 'Twiggy style' graphite of the mid-70s had mostly disappeared by the mid-80s.
My next Browning fishing catalog is from 1988 and the Silaflex trade name was no longer used for graphite rods, only fiberglass.
Tom