I took the easy way out for a 400 power switch. Didn't want to drill a hole in the face plate.
Got a small project box, stuck in an AC line cord, single AC outlet, a 30A toggle between them and screwed (shallow screws) the affair to the side of the chassis. Left the stock power cord intact.
Line cord into the wall, amp's AC cord into the box's outlet and I got a side mounted power switch. Face plate is unmolested and the switch box can be removed anytime.
I don't have a wood sleeve so it works for me.
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