Will this schematic work?

Hi all, got a band that "needs" an insanely loud guitar amplifier, so I figured I would build them something in the 300w range.

I found this schematic on google, does it seem trustworthy? I am thinking this circuit and a 2 channel jfet based preamp should sound good enough considering the application.

Any thoughts or suggestions?
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I can sell you for 100 euro, or you can buy elsewhere, PA amplifier.
I have Solton Craaft 1400, that's some 2 x 600 w at 4ohm, I think 2x 380W at 8 ohm. Bridgable to mono for 1.2kW nice value for guitar 😂, 70 volt rails with 4 parraleled 2sc5200 2sa1943, total 16 nice Toshibas...

This is just example, what I mean is to buy s/h PA amp is way cheaper and easier way to get a lot of power for a band 😅