This may be a matter of getting words switch, but the Evp is in the car the Condenser is in front of the radiator. So I am assuming you meant to say you removed the STV from the evap. The unit attached to the condenser is a Dryer, and yes that needs to be replaced. The Dryer is a critical part of the system.
If you got OEM rings that are on the market today they are most likely R134 compatible. As a side note; all R134 parts, other than oil, are also so R12 compatible.