Spectro Acoustics 500SR

Hello. I'm trying to repair a Spectro Acoustics 500sr amp . It appears to have 4 blown output transistors. Is there a suitable replacement for the Motorola 150-0068 ?
Does anyone know where I can find a schematic for it. HI-Fi engine shows one available for download but they're not taking any new registrations,so I'm unable to get it. TIA.