Any info about the Marantz SP 208 Speakers?

[Spareribs]

I was at the Goodwill today and I bought a pair of Marantz SP 208 speakers for $8.97. They are about the size bookshelf speakers but bigger though and they sound really good! My current speakers are the Insignia book shelfs but I immediatly replaced them with these Marantz speakers because I like the sound stage much better.

I tried to google these speakers but couldn't find any info. They look like vintage speakers with that traditional box look perhaps from the 70's or 80's.

Any info on these? Anyone know when these speakers were made?