They will have the smaller diameter internals I reckon. Have you thought of the early style hope disc brake for forks without tabs? Not sure how easy they are to come by though and limits your hub choice.
The hope mechanicals that LGF pictured are medium-hard to get hold of - I've seen/been offered 4 sets this year of actively looking. Never seen a set with a judy clamp - 2 girvins, a manitou and a pace. Might also be worth looking at hope c2 hydraulics as they also had a bracket option. As Ishaw says it does limit your choice to hope hubs with a short body and long axle on the disc side - but they are fairly easy to get hold of. Other manufacturers did them too.
Happy to measure the ID of any of the clamps I have - manitou & RC35 in mechanical and RC36 in c2.
I think yours are '96 while mine are '97. They changed to a single casting for the sliders in '97 and might have change the stanchion diameter too. I did a lot of research before shelling out six hundred notes for these way back... I'll take a few measurements tonight to compare them to yours.