Thumb turn for Patio side doors

I am looking for the thumb turn part that opens the side doors on my patio doors. It is solid brass and there is nothing wrong with it. I just would like to change it to a satin nickel finish. No markings on the hardware but the following markings on glass. GUARDIAN GENEVA NY BS 6208 1981; 16CFR 1201 II; CAN/CGSB-12.1-M.

I discovered that it is a Stanley door. The labelis painted so i can't quite read the numbers. The following numbers are imprinted on the edge: O5D14V0PB