The speakers you are looking at likely had a grill cloth covering the inside front originally (if only that mid/high section up top is black). I believe you could still get replacement grill cloths from Klipsch parts. The serial numbers for those speakers were on a piece of paper that was stapled to the back of the speaker. In their absense it may be difficult to pinpoint the exact date, but I'd guess you were looking at a pair from the mid 70's - early 80's based on the black front and oak body (assuming I'm understanding you correctly). Also they changed the horns from metal to plastic at some point (I think around the mid to late 80's, but could be wrong there). They also changed the drivers around the same period. The earlier ones with metal horns likely will have the K55V drivers, which are preferred by many. To get far more information than you'd ever need on this subject go to:
Klipsch Site
Click on "Forum" above. Sign up and ask whatever you need to know, or just do a search in the archives (though the search engine is rather particular so make sure to adjust the date range). The metal horns have been criticized as being a bit harsh, which is easily solved by using damping material like Dynamat on them. I own a pair of La Scala's which are likely the same vintage you are looking at. K55v drivers, metal horns damped with Dynamat, Type AA crossovers (those were also replaced later on, though the AA's are arguably the better version). I also replaced the stock wiring harness with silver (DH Labs) wires. Fantastic speakers when paired with the right amp (SS need not apply here!! Tubes are definitely the best way to drive these speakers). Extremely efficient. Remarkably detailed. Just wonderful speakers!
Klipsch Site
Click on "Forum" above. Sign up and ask whatever you need to know, or just do a search in the archives (though the search engine is rather particular so make sure to adjust the date range). The metal horns have been criticized as being a bit harsh, which is easily solved by using damping material like Dynamat on them. I own a pair of La Scala's which are likely the same vintage you are looking at. K55v drivers, metal horns damped with Dynamat, Type AA crossovers (those were also replaced later on, though the AA's are arguably the better version). I also replaced the stock wiring harness with silver (DH Labs) wires. Fantastic speakers when paired with the right amp (SS need not apply here!! Tubes are definitely the best way to drive these speakers). Extremely efficient. Remarkably detailed. Just wonderful speakers!