Truth # 45251, I have both right-handed and left-handed which I want to replace with white.

I have both right-handed and left-handed operators which I want to replace with white. I need 3 of each. In addition to the #45251 which is on each of them, there are additional printed numbers such as 07122002, 07152002 or 07292002. My belief is this is the 15.3 Traditional Split Arm Operator which has been discontinued? But I don't know what the replacement part would be. Also wondering if I can use this same hardware but cover it with a white plastic cover and a new white handle, which I believe my contractor did a few years ago in other parts of my home. See photo of the white plastic cover....i believe he used this to cover this exact same old hardware.