[EICO] Eico 720 cover question

[shoppa_eico at trailing-edge.com]

OK, now the electronics in my Eico 720 are OK again, and I go to put
the top cover on.

On the side rails towards the rear there's an obvious hole for a
screw of some kind.  There's also obvious clearance holes for a screwdriver
on the bottom cover and matching holes on the top of the chassis.  And
it's also perfectly obvious from the bends in the top cover that a
previous owner had extreme difficulty getting the cover off in the
past too.

So how does all this go together?  It looks to me like there are
lockwasher marks in the top cover where it got bent.  But there's
no obvious access to any kind of fastener (screw or nut) from the
top.  Were there some captive nuts/screws involved originally?

The 720 manual on BAMA doesn't cover mechanical construction
unfortunately.

Tim.