[rescue] r-square disk boxes

[Joshua D Boyd]

I have a pair of r-squared scsi disk boxes (no model number listed, part number
is 59072).  For the life of me I can't figure out how to get this open.  

There are four screws around the fan.  I tried unscrewing them, but I can't
get them to come out (the unscrew, but don't come out).  I see no evidence of 
411 style latches, and prying at all the cracks yields no clues either.

-- 
Joshua D. Boyd