DOD made multiple pedals from that time that are rated for a 10v power supply. Of course, it’s an oddball voltage. Players have tons of 9v power supplies. Almost nobody has a 10v supply. Fortunately, there are players all over the internet that have reported that DOD 10v rated pedals will run off a 9v supply.
Will the pedal operate and sound exactly the same at 9v as it does at 10v? Maybe not. It could affect headroom. It could affect the maximum volume output of the pedal. Since it’s a dirt pedal, it could affect the way it clips. Try it and see what you think. If you like the way the pedal feels, sounds, and operates at 9v, then you’re fine.