It’s most likely an open bath damper, so I wouldn’t on the damper side. Unless you wan’t to completely change how the fork handles, it might end up worse.
What I find with those old Floats is the oil on the air spring side migrates up the fork to the air chamber, reducing the volume like tokens, but over a period of time whilst the user set air pressure remains the same. Hence why they start to feel harsh over time.
You will probably find the full 30 ml of lower oil mixed with the blue stuff above the piston. I understand you can change the seals for a better version, bear in mind the originals were not that effective in the first place (I’d say a design fault), hence why Fox recommend regular service intervals!
I empty the oil from the top back into the lower every so often. Or let some air out when they start to feel harsh.
Do the service though, especially if it’s not been done for years. It’s usually Fox Green, 160ml on the damper side and 30 ml on the air spring side, with 5cc of Fox blue above the air piston. Fox publish a table with the volumes.