Create Regular typeface from Multi-Master Skia.dfont

I have the 'Skia.dfont' as was installed by default on Mac OS X 10.5. This is a Multi-Master font. I want to create several Single-Master fonts from 'Skia.dfont'. The problem is that I am trying to replicate the 'Regular' Weight&Width. When I select 'Tools > Multiple Master > Generate Instance' none of the Known Instances in the drop down menu (displaying the size 72 Pt 'ABCabc123' text in the preview box) match the same text 'Skia Regular 72 Pt' entered in a TextEditing application. The default 'Custom position selected' uses Weight 500 Width 500 but this is also not the same as the text using the Regular Typeface. I use a Text Editor that allows me to set window transparency which I place over the same text in the "Generate Instance' window and adjust the Weight & Width sliders to get an approximation. This is proving to be very tedious, it seems impossible to get a perfect match.

Is there a better method to achieve this? Perhaps the Weight & Width values are reported somewhere to reflect the different Typefaces used by this font based on the Font palette in any application in Mac OS. I really want to know the values of Regular and Bold to generate a Single-Master Regular and a slightly modified bold closer to medium-semibold font.

Any ideas would be highly appreciated.