Too many Remakes of F & E units and Museum pieces are what dominate O gauge, Sadly.
I'm holding on to my custom painted O gauge equipment, but have been purchasing stuff in HO (which is not available in O) SDP45, SD40-2, GP40X, GP40-2, GP50, SD45-2, U36C, B23-7, B30-7, B36-7, F45, SDF40 etc.