Hi,
Here is what I gathered as evidence on these old Royal Heavy Duty Commercial vacuums that were sold through the spring of 1987:
Models 605, 605A and 608 are related to the 880 in that they have the deluxe headlight. Model 608 replaced the 605A for 1977.
Model 611 is related to the 602 due to the shape of its nozzle and headlight.
Model 606 is related to the 801, again, due to the shape of its nozzle and headlight.
~Ben
Here is what I gathered as evidence on these old Royal Heavy Duty Commercial vacuums that were sold through the spring of 1987:
Models 605, 605A and 608 are related to the 880 in that they have the deluxe headlight. Model 608 replaced the 605A for 1977.
Model 611 is related to the 602 due to the shape of its nozzle and headlight.
Model 606 is related to the 801, again, due to the shape of its nozzle and headlight.
~Ben