aterpster
If it is necessary to operate at a speed in excess of the upper limit of the speed range for an aircraft's category, the minimums for the higher category must be used.
For example, an airplane which fits into Category B, but is circling to land at a speed of 145 knots, must use the approach Category D minimums. As an additional example, a Category A airplane (or helicopter) which is operating at 130 knots on a straight-in approach must use the approach Category C minimums. See the following category limits:
The first part of of you post that is highlighted is correct however you are using the wrong speeds when selecting which category minima applies.
As you stated a Cat B aircraft is one where VRef falls between 91 and 120 kts. However the maximum speed inside the final fix for a Cat B aircraft is 130 kts and max circling speed is 135 Kts so the Cat A aircraft operating at 130 kts can use Cat B minima for the straight in approach and not Cat C as you stated.
The Cat B aircraft you mention at 145 knots can use Cat C circling minima as the max Cat C circling speed is 180 knots.
The table in this Wiki article lays it out quite clearly.
Aircraft approach category - Wikipedia, the free encyclopedia
With further reading I see the FAA and some other jurisdictions do it differently and just as aterpster quoted.
It's just as well we all do it to the book, just depends on which book.
