Good solid TW speakers. These have DCM woofers and Philips tweeters and work great, like power and don't break. The end caps will respond nicely to a refinish. I used Watco Danish Oil Finish Dark Walnut and the came out better than the original pair I still have from new. The TW had a few different iterations before they settled on what you have. I don't have the serial number breakdown of that but something below 10,000 I guess. You have what most have and love. Replacement grille material is the air filter foam material and it is held to the speaker by two vertical strips nailed to the back of the unit on each side of the labels, grille material glued to the plastic strips used on the later models. Earlier had some wood strips.