I have some bare filter boards for the QSF-06 and SPF-08 Elad Preselectors. You can build the filters per the Elad schematics. I have:
CS-B3.1.0 2 each (3 coil) board)
CS-H5.1.1 1 each (5 coil board)
Price is $10 for all three boards, including shipping and PayPal fees.