I just fully rebuilt my first 2-stage dry clutch this last summer, but it was also on a Kubota. L2550DT. There IS a
window as you describe, to access and adjust the fingers for the PTO clutch. Unfortunately, it was underneath the
FEL subframe, which has to be removed.
In this situation, the road clutch was burnt out, but the PTO clutch was pristine. The PTO clutch can be stuck to
the pressure plate independent of the road clutch. I had a shop set up the new clutches and fingers to spec
in their shop. It cost $600 for the shop part of the rebuild, which was a shock. I did all the splitting and
assembly/reassembly of the tractor myself.