notehead half metrics

From bravura_metadata.json:

        "stemThickness": 0.12, 

        "noteheadHalf": {
            "splitStemDownNE": [
                1.056, 
                -0.388
            ], 
            "splitStemDownNW": [
                0.1, 
                -0.452
            ], 
            "splitStemUpSE": [
                1.256, 
                0.456
            ], 
            "splitStemUpSW": [
                0.316, 
                0.396
            ], 
            "stemDownNW": [
                0.0, 
                -0.196
            ], 
            "stemUpSE": [
                1.364, 
                0.192
            ]
        }, 
=============
I multiplied your numbers by 250, to convert back to font design units.
stemUpSE[0]: 1.364 × 250 = 341
stemUpSE[1]: .192 x 250 = 48
stemThickness: .120 × 250 = 30
=============