Audio Research EC-22 with 12db/octave 110hz filter cards

This EC-22 is supplied with 12db/octave 110hz filter cards and is near-mint. It's missing one top cover screw and there are some marks around the screw hole as pictured. Function is 100% , but the crossover point is a bit low for my application. Sound quality is stellar compared to the JL CR-1 I tried.
Per Wendell at Magnepan, these would work well with early Magneplanars that allow bi-amping such as the MG3, 20.1 and Tympani as well as some Vandersteen models. Do your own research before buying please.
Different filter cards are NLA from Audio Research, so please be certain the supplied cards will work for your application as no returns are accepted. 
As of 2015, Phil Marchand at Marchand Electronics was willing to look at  building compatible cards at different slopes and center points, though I have no idea whether that's true today.