Steve line stage is quite a common topology of the era. HH used a similar one in their power amps IIRC. Basically an op amp with a current boosting class B stage added in the loop. Soundcraft use pretty much this same circuit today for their headphones amp. I think Doug Self shows it in his book.
I remember trying to build discrete version of the DRV134, late 80's I think, a miserable failure, since 1% R's were not easily / cheaply available, for some reason I still dislike that circuit, but I don’t do much audio stuff these days, but I'd probably just plonk a THAT16xx in now