I haven't seen most manufacturers publishing unweighted SNR, so I have no idea.
But why not just snap to the weighted version that everyone uses and, in SOTA's case, claim a higher number >80?
Actually I just remembered that rumble figures as a whole maybe somewhat meaningless anyway. I think sometime during the 1970s they had to develop new devices and measurement techniques in order to quantify the rumble because using a test record to do so was pointless. Turntables had reached the point where they were quiet enough that simply using a test record didn't give useful results (the noise from the table was below that of the surface noise you'd get from just normally playing a record/the amount of noise present from the cutting process). Thorens invented a device called the Rumplemesskoppler just so they could get some measurements.