The only resistor I can clearly see in the first pic, just this side of the RMC 470pf ceramic capacitor is the load resistor yellow, violet, green, red, brown is 47.5k ohms at 1%.....it also appears the phono stage is pretty much identical from the C31 thru the C38 except for the DC input blocking cap......both 10 mfd, polarized and non polarized are used.
My C35 and C37 schematics are not available right now but I laid open a C31 schematic and compared it to your photographs.......not much difference....
It appears the resistor soldered to the RCA center pin is brown,black,red, gold; 1k at 5% stock value for C31 thru C38.....
I think they are telling you a tale........sorry.
I would concur though that you are approaching over driving your Adcom amp with the Mac preamp.