Help with Audion reference phono-preamp

Hello all,I was given a Audion reference phono preamp.Its from the late 1980's,designed by David Chessel. Its had quite some fiddling with, and may or may not be fixed bias?I have looked at the post from Nov'09 by nightpuma on his Audion ref P-A. restoration and am tempted to use his circuit. My Question is this; Do you know if it was fixed or cathode bias? Is nightpuma's circuit correct for RIAA? .Thanks for your help.
Audion preamp

Background,nightpuma's Audion circuit is cathode bias,SRPP ECC83 x2 with passive RIAA between the first two sections followed by a buffer. My Audion circuit is/was fixed bias SRPP + buffer but not the same buffer circuit.
I dont have any links.Nightpuma's circiut is in his post of Nov '09 on this forum.