The model "KDFR" stands for Klipschorn -- D-Style (decorator), with a finish of Fir Raw (unfinished). Basically the finish is just raw plywood, not even birch. I don't have the SN decoder handy, but the "E" in the serial number will indicate the year it was made.
Based on all of the above, and the condition they are in, even with today's inflated prices, I'd estimate their value at about $1200. If someone offered $1000, I'd take it. This is probably not what you wanted to hear, but we're all just trying to help you establish what you would likely be able to sell them for.