Supposedly the Lemans I had thinner fork tubes for lightness. I have never seen this, but it wouldn't surprise me if they could hold a bit more oil because of this. Since the oil is for lube and darn little else. I'd run 50cc or maybe 60cc, and be done with it.
After years of trying to pour the oil into the gap between the damper cartridge and the for tube (with burping of oil back out), I started assembling the damper/spring assembly into the fork lower, pouring the oil in (the now much larger gap without the fork tube in the way), and then insertng the lower/spring/damper assy up into the fork tube. Much easier.