Jim:
It should not matter whether the Atlas shell is ABS or Styrene. Both plastics will bond together (ie the plastic will melt using a general purpose glue like Plastruct Plastic Weld). If you are using a glue like Plastruct Bondene then yea it will matter since this type of glue is good for bonding like plastic to each other (ABS to ABS or Styrene to Styrene). Just look at the instructions on your glue bottle to see if unlike plastic can be bonded.
The bigger issue is if the shell is neither styrene nor ABS but some plastic that normal plastic cements don't work on (think Korber models). In this case you will need to use super glue or in the case of some modelers hot glue. The easiest way to tell is to try bonding a small piece of your styrene stock to the shell in an out of the way place using a general purpose glue good for attaching styrene to ABS. If the plastic melts you are good to go. If not then super glue.
Joe
