Sorry for the late reply here.
The values on the PCB are correct. There are two versions of the Muzzle PCB, through-hole and SMD.
There's no difference between them aside from some components moved around to accommodate the different sized IC.
I'll get the new build docs up as quick as possible, but it's mostly just redundant information... The BOM is the same, and the values / part markings on each PCB are correct for that particular version.
If you're only getting squealing when using the Key input you probably need to check your wiring.