Oops.
Most of the rest of the stuff is interchangeable. Fenders, gas tank, seat, etc. will bolt on. There are some differences and they are shown in the parts catalog downloadable from this site and others. For instance, the 175DT headlight also holds the speedo, whereas on the 200 the speedo is separate. However, you can use the 200 speedo and headlight to replace the headlight/speedo combo on a 175. The 200 has a front brake light switch that the 175 didn't, affecting the wiring and the brake lever handlebar perch. There are paint and seat cosmetic differences, also.