I remember someone such as Brian (eurekaprince) or Jimmy (rugsucker) mentioning something about there initially being 2 different throw-away bags - style f and style g which may have been designated for the automatic-type and super-automatic type (not sure). Anyway, they debuted with the Super Automatic S-255 in 1956 according to advertisements and later became combined as the well-known F&G style.
I'm unsure if there's a quality difference between the OEM bags and knock-offs. I have never personally seen an older throw-away Eureka bag older than the mid-1970s, which included installation images; although I'm sure someone else can post photos of them.
The photo's below include:
1) Mid-1970s OEM bag package front
2) Mid-1970s OEM package close-up of model series compatibility
3) Mid-1970s OEM package close-up of cleaner line drawings
4) Mid-1970s OEM package package back
5) 1954 ad (supposedly) featuring the Roto-Matic canister model 800 and Automatic upright model S-250A
6) 1955 ad (supposedly) featuring the Super Roto-Matic canister model 800-A and Super Automatic upright model S-255
7) 1956 ad featuring the Super Roto-Matic canister model 910 and Super Automatic upright model S-255
