Hello Gerry,
Considering you bought the amps built, it does not seem very silly to mix up the plate choke and filament choke.
Yes, roatating the 4-pin socket is tough if you stick with the stock socket. There is a teflon socket with a black retainer ring that would let you rotate everything, you'd just have to be careful about getting things hooked back up properly.
As far as deadening the chassis, there is a ton of iron on there that deadens things pretty well, though I am familiar with the noise the rocker switch makes when you switch the amp on. I have seen some people go to the hardware store and buy some 1" x 1" lumber, cut them to 2", and glue them into the corners of their bases, then drill holes in the corners of the chassis plate and screw the plate into the base.
This always seemed overkill to me on something that weighs as much as the paramount.
Otherwise, you could get something like Dynamat and cut it into long strips, sticking them all the way around the edges, but I think ultimately you'll just end up with a bit of a mess.
-PB