That is exactly what I wanted...until I just learned that your 300B headphone amps have speaker taps!
Being able to flip to speakers when I get up to mix a cocktail is a key feature of my Spud!
Using the leftover parts is very cool but I know it is a lot of work - trial and error - to get it right.
I'm very interested especially as you have leftover chassis and parts...The Puttanesca Amp...
Sounds like a amp thats been used one too many times.