I won this Eureka on eBay yesterday. It is a 4 amp model, and I believe it takes F&G bags. It should arrive next week. When was this machine sold? Also, was it a TOL, MOL, or BOL model?
I would guess that this is a Mid Line Dial-a-Nap upright from the mid 1980's. Your key to dating this is the slanted font used for the "Eureka" lettering. This lettering was not italicized until the mid 1980's, just before the arrival of the Bravo uprights with the radically different side-facing motor. Before that time, the letters stood straight up as on the Ultra and Precision uprights of the early 1980's.
on the bottom of your base off to the side you will see a time dial looking nub called a nipple. get a flash light and you will see two numbers. This will be the date. I bet you will see 89 on it.
The front lens of the headlight should just snap off with the help of a screwdriver, if I'm not mistaken. Inside you'll find a standard vacuum or sewing machine light bulb with a little nipple on it. It is installed with a short twist of the bulb.
Eureka first implemented a date code in their serial # starting with the 1989 models. However, the date code in this case consists of the year and the week of that year.
Which means: "9108" would be year 1991, week (not month) 8.