Antique sound lab hurricane

Hello can anyone explain how to set each for the tubes bias I know there's controls for each how do you know the level of the bias it must be on the display how do you get the display to show the setting.
On each side panel there is a selector switch for each of the tubes. Select a tube and then adjust using the setscrew adjustment for the selected tubes. If you are using KT-88's adjust bias between 450 and 500 on front meter. I found that 480 sounded really good. Don't set above 500 or you will really shorten the life of the tube. Good luck
Thank you for the response how do I get the bias level to show on the front meter