It is trivial to over-spec the voltage and current ratings. It literally costs only pennies.
You did not identify WHAT machine you are working on, but if it uses tubes, beware that a modern solid-state diode is much more efficient and could over-stress the circuits. Research replacing selenium rectifiers with silicon diodes. I suspect you will find that inserting a series resistor is recommended to emulate the voltage drop across the original selenium rectifier and save the filter capacitors from damage, and the circuit from over-voltage.
Suggested reading: http://w3hwj.com/index_files/RBSelenium2.pdf