Hey guys n gals.. I was just curious I recently acquired a U4103 convertible estate.. Metal based.. Took it apart and noticed it had a plastic fan and a metal top cooling fan.. I've also seen plastic convertibles with metal impeller fans and plastic top cooling fans.. Was there a reason for this? Was this possibly a phasing out of metal parts to plastic? I know this particular u4103 phased into plastic bases... Just curious if anyone has encountered mixed metal and plastic fans tops/bottoms