Removing panels from a DEC rack, and MicroVax current draw...

Well, just when I had thought that I'd had DEC racks figured out, I tried to disassemble this one. Now, every other DEC rack I've worked on, you just have to lift up (sometimes pretty hard) on the side panels, and they pop off. Not this one. This is a MicroVax 3900, that I have decided, likely against my better judgement, to install in my second floor computer room. Before it goes in there, I need to give it a good cleaning, and I'm going to bring it up in pieces. So far, I've gotten the RA90's out, removed the top, back and front, and now I'm trying to remove the BA213 from the rack. And, in order to do this, I need to take off the little latch/metal tab that holds the front door shut. It's held on with two screws, that can't be reached unless I remove that side panel. Upon closer inspection, I see that these side panels are somewhat different than the ones I'm used to. They are made of plastic! Yes, while they have the same white-edged, black side appearance, they are made of a thick, bombproof plastic rather than the usual metal. They won't lift off, I've put a fair amount of force on them, and they just won't pop off. I can't see any kind of retaining screw or tab, and I'm at a loss. Accoding to the back of the top panel, this is a Model 655QF-AZ, series H9644. Any ideas? Another thing I wonder about, is just how much juice will this sucker need? I have two RA90's, and the MicroVax 3900 system (BA213 chassis), with one RA70 in it, and a decent population of cards. The power distribution unit that came with the cabinet sports a 30A power connector, but I know that I should be able to run this off a regular 15A circuit. Question being, can I run anything else off that circuit too? -Ian