Looks like Single Ended.. the lower parts is there to counter the upper part to null the dc current passing in the opt to avoid saturation...
The impression I get from this is that the driven output tube operates as a common cathode type, while the bottom tune operates grounded grid. The upper tube inverts, and the bottom tube doesn't, so you do get phase inversion. Problem is, the grounded grid bottom tube has a very high plate resistance as compared to that of the upper tube, so I would think that there would be a serious impedance mismatch problem.
It's worth looking at RDH4 and the comments made about circuits of this type.
The label on the schematic notwithstanding, this isn't an SRPP. Distortion and overload recovery will not be inspiring.