Head Unit Swap?

I have a 172 aswell as my 197.

Now the 192 has a single cd unit, and the 172 has a cassette player in the dash, with a 6 cd Changer.

Anyone know I I could swap the two over and have the cd changer in my 197?

Help would be appreciated.
 
Sorry can't answer your question but interested to know if the 172 headunit fits the 197 hole correctly.

The 197 head unit is slightly curved so have wondered if it will fit the same.
 
Any ideas?

There is a 6CD option on my 197 head unit when I scroll through the sources.

Would it be a case of, removing the changed from the 172 and fitting into the 197?