Well, since you struck out twice, I'll take a stab.
If Audiokarma didn't get any info for ya, you're really SOL.
First off, I'm not familiar with the equipment itself but I do have some familiarity with the market since the early 60's. Here's my guess, and why.
The fact that it's a synthisized FM tuer pretty much rules out the golden age of the seventies amd plants us firmly somewhere in the dark ages of eighties.
In the eithties, many manufactures prostituted their formally good names and churned out mediocre (and I'm being charitable here) rack, or all-in-one system packages. This includes Fisher, Marantz, Scott, Fisher and who knows who else along with Kenwood., all turned out some impressively gaudy looking, underpreforming stuff.
I believe that CD's quickly became part of the mainstream by the mid eighties. Since a CD player is not part of the system, I'd have to place it somewhere in the first half of the eighties or part of a low-line system in the later part of that decade.
As for the speakers, many that were designed as part of "the system" were designed to look impressive, yet still tended to lack somewhat on the sound. IOW, more and bigger is not always better.
It ain't no Marantz 7C/8B/10b combo but if you're not paying a bundle for this, it's a decent starting point. As long as they are not dependent on each other for power, you can upgrade each piece as you see fit. I'd most likely start with the speakers.
