Most all of the same information is available for free at www.acsource.com.

Since this is a system that was originally 134, there should be no need to flush the entire system. There is information on that site that gives an idea of how much and what kind of oil to add when replacing a given component. For instance it is probably about 2 oz. of oil that was lost with the evaporator replacement. There are three different weights of PAG oil, so you will need to find out which to use.

Yes, you should indeed replace the r/d since the system has been seriously opened up. Then you will need to evacuate, preferably in warm weather or with major components artificially warmed up to summer weather temperature in order to boil out the moisture during the evacuation process. Evacuation should be done with a good wet vane pump.

Then charge properly with gauges in place.

There is probably an auto air shop in your area that could evacuate and charge the system for you at a reasonable cost. You have accomplished the really expensive and tough part of the job. Congrats for that.

Good luck,