You are very welcome.
One thing I did just notice for the first time is that the cylindrical section of the barrel (in this case the .900" section) is the same on my TypeA and TypeB 10.75mm rifles. The rear sight on the B is shorter though so the stepped section is longer out in front of the sight band.
My supposition is that the barrels were turned the same for both and the differing sight bands used were either A or B type rifles.