LesinUtah
Les,
The Tradition was 1979-1981, actually... and yes, multiple versions (aside from the choice of disposable bag or shake-out bag) did exist:
Summer 1979: with speed switch mounted to inside of headlight cap, and headlight lock button. All front-mounted accessories (rug nozzle, hose, Crystalator, Miracle Head, Handi-Butler and Rug Renovator) have a metal pin to jibe with one of the two buttons of the new-style speed switch (only the hose uses the high speed button).
Fall 1979: speed switch re-located back to fan case below suction intake opening; headlight lock still intact, but will be discontinued shortly after.
Winter 1979-80: suction relief vent removed from rug nozzle.
Summer 1980: new gray Lexan fan, wheels now treaded instead of smooth.
Winter 1980-81: ribbed foot switch instead of smooth, and new-style air intake nozzle (same as the one for the Heritage and later machines, but in blue).
The fall 1979 to 1981 iterations would all have had a blue rubber boot over the speed switch (which also goes inside the fan case) which, like the very first Traditions that had the speed switch mounted to inside the headlight cap, ensured that no moisture would get inside the motor while the Rug Renovator was used.
All iterations of the Tradition before the summer of 1980 had the 10-blade metal fan and the smooth wheels (no tread).
As to the Heritage 1HD (1981-1984), the 13" nozzle was first made an option in late 1982 or early 1983, after the COMVAC 1300 had come out.
And lastly, to answer your question about my 1979 Tradition's headlight lock cap, I have not yet gotten around to it, but maybe sometime soon.
~Ben