I owned a 576 for a time. While I loved the gtr, the thick body & that cutaway are a terrible combination: my fretting hand kept getting trapped while playing high notes
I regretfully sold it.
The Roy Clark is probably a better design, with a thinner 535 type body.
I like the SF better: they are excellent amps for pedals
SF twin is all over "dark side of the moon" for example
Beatles "let it be" too
I let an amp tech convince me to blackface my SF and I was disappointed in the results