Reverse wippens for old chickering

[RustRazor@AOL.COM]

I need to replace wippens in an old Chickering Grand.  The wippens are of the 
sort where the bushing for the wippen flange is in the wippen - not in the 
flange...kind of similar to the standard hammer flange assembly.  The wippen 
flanges are the flat brass ones similar to the billings flanges.  

Anyone have a source for these things?...or suggestions about adapting a 
modern wippen to this situation?  Schaff and APSCO do not have these 
available.

Thanks - Matt Wynne, Suffolk, NY chapter