Typically on the Acoustic gear I have - those 4 Phillips screws allow the chassis/housing that encloses the amplifier section to drop down ever so slightly and then is fed out of the cabinet case itself.
So far - all my Acoustic stuff has the amps slide out to the rear. It would not be impossible that your unit - to which I have no privileged personal information nor experience MIGHT come out through the front.
Many Peaveys are like that and one has to also remove the corner guards to facilitate their removal.
The wires to the driver(s) are indeed sealed into the cab top which is the enclosure for the driver(s) and is sufficiently long to allow you to reach into the amp chassis and unplug them from the PC board long before you run out of wire length.
Inside the Acoustic amps I have (B600H, B-450, B-200H) - there is a fuse that has a soldered SFE/AGC-form receptacle for the replaceable fuse.