VERY RARE: Micro Acoustics QDC1e

Recently unpacked storage items and found my carefully packed Micro Acoustics QDC1e phono cartridge (w/stylus) I purchased in 1969. My notes from the storage inventory indicate less than 100 hrs of use with an AR-XA turntable at under 2 grams tracking force. I tried it out on a restored SL1200 mk5 at 1.1 grams tracking force and listened using a restored Dynaco PAT4 through a Yaqin tube amp driving AR3a speakers. It sounded great with no discernible L/R channel difference. No literature or box with it though. My question is this - does anyone think this cart has any value? If so what's a good guess as an asking price?