Help with newly acquired speakers?

[dibmem]

Hello all - First off, this is our very first post, so we apologize ahead of time if we didn't do enough research on the forums before posting...

My wife and I are owners of several sets of JBLs (L-88 / L-166 / L-65) and we love them all! Unfortunately, our house isn't big enough to have all of them set up at the moment, so the L-65s are our primary speakers - they rock.

We have purchased another set of speakers today but have been unable to figure out exactly when they were made, etc...

Label on the back reads: "D-48 S-5 WX"
We have found only that the WX means walnut oil finish, but would like to know approximately when they were manufactured and (if anyone has the info) operating info. There's quite a few connections in the back and we're a little lost.

Thanks in advance!

*edit*
We've taken some pictures to help with information.
Yes, those are casters on the bottom of the speakers - Anyone have advice on how to fix the holes that will be left when we remove them? They each have four tiny screws per wheel.