'91 200TQ - which power steering fluid?

[Bart Oleksy]

My level's low, but the local "import car parts" shop had two kinds:
 11S and 7.1, and wasn't entirely sure about which one to use.  He
*thought* that originally my model would have used the 11S type, but
I've only had the car 2 years or so, so I'm not even sure if it's still
on the 'original' style fluid (if that's even correct).

I had heard some story about putting the wrong type in could wreck the
PS pump, so I'd like to get this right the first time.

Is there a way to tell which type is currently in use?  Is the 11S kind
the 'right' one for this model/year?  Thanks.

Bart