2114? 1K * 4 bits?
I still have an unused 2.1 KHz Collins 455 KHz mechanical filter I bought at the Dayton hamfest years ago. Its a little narrow for voice, but it would be good for CW.
I still like Collins equipment, just not their poorly designed CATV equipment. I wish I could afford a R-390 and felt well enough to do a complete restoration. :(