The original Big bellybutton Bird wasn't a D-30, nor was it a D-25. It was most likely a D-27, D-28 variant. The tail fillet was a field-applied modification, but the aircraft did not have the tail fillet at the time of the sole Fw-190 kill. It did receive the fillet later on, so you can technically use this skin on either bubble-top D model.
I have some photos of the original aircraft (the 1944-45 version, not the airshow version) that will post up later on.
J