@lux1521
The cast headlight models go way back in time, to about the late 1930s. The last ones appeared on commercial-duty (662, 663, 672, 673, 682, 683, 692, 693, 1040, 1060, 7620, 7630, 7720, 7730, 7820, 7830, 7920 and 7930) and the 90th anniversary edition model (89103).
The thin nozzle had historically been used on models 601, 602, 603, 604 and 611. The 611 was a low end yet very popular commercial model sold in the years 1977-87. The last such upright to bear this nozzle design was model 883, which took over for the 881 during 1988. The 883 had a new 5 amp motor.
The 994, introduced in the spring of 1990, was actually the first model with the 7 amp motor. The 992 (993 similar but with dark blue attachments included) had the same 6 amp motor as the 886/887, but it also featured the Au-Toe-Matic toe-touch height adjustment control.
The square headlight assembly first showed up on the model 880 in 1966 (the deodorizing chamber was at first exclusive to the Electro-Hygiene models). The 880 also had a commercial-duty equivalent in the 606A between 1966-76 and the 608 between 1977-87.
~Ben