[Elecraft] D-104 Mic Element Replacement

[Wilson Lamb]

OK, discriminating operators, does anyone know of a good replacement D-104 element. 
Yes, I have been on the web and see dynamic and electret replacements.  My uses don't involve electret empowered radios. 
I also see statements that all the ceramic replacements have been sold, but I hold out hope. 
Does anyone know of a good ceramic element? 
Does anyone know if the dynamic/transformer replacement is near the same sensitivity as the original crystal? 
I have three D-104, one of which was my dad's, from the 540s.  It's lost its midrange. 
Thanks, 
Wilson 
W4BOH