Check Crosley Model 6615:
http://ww3.nostalgiaair.org/schematics/CRO/_CRO_7-75.gif
Your 6C7 should most likely be 6B7. A 6C7 was only used my Majestic.
Norm
:I have a crosley 6 volt sixer.I do'nt know what chassis number it is.The tubes are:2-15's,6A7,6C7,31,and ,38.It looks alot like a buccaneer but that one did'nt have the right tube set.