More muddying of the waters-
"The earliest version of Autumnglo was simply shaded brown. The middle clear areas on most of these old guitars have yellowed, but wasn't originally apparent. The next version was just Fireglo laid on rather heavily. The last version was back to that original brown, but in a satin finish, while the gloss version of that color was designated Walnut. So when someone says Autumnglo, you always have to ask WHICH Autumnglo?" (John Hall, posted on the official Rickenbacker forum February 2000).
"There's so much confusion about Autumnglo and how it changed. In the early 50's it really was it's own dye but by the end it was just dark Fireglo" (John Hall, posted on the Rick Resource forum, November 2005).
I have a similar conundrum to your self. For years I believed my '80 was Fireglo until getting hold of Paul Boyer's book. Then I was almost convinced that it's actually Autumnglo. I had a discussion about it on the FB 'Rickenbacker Bass Guitars' group and plenty of people chipped in who had Fireglos that were a darker shade of the burst (the standard Fireglo is brighter, almost a cherry sunburst). There ended up being no consensus apart from the fact that Fireglo has varied over the years due to various factors- the shade of paint used, whoever happened to be manning the spray booth on any given day and the fact that the varnish yellows over time, which changes the hue of the paint. The other thing we agreed on was that the black scratchplate on mine fools the eye and makes the red look darker than it actually is.