I can't say that I understand fully what I'm doing, but, I made use of shermanp's script ReadifyFont
https://github.com/shermp/ReadifyFont and generated what I called 'LelujaNew', loaded it along with an epub called FontTester and seem to have no issues seeing 4 distinct styles and only a single font name LelujaNew.
I used the commands
Code:
fontforge -script ReadifyFontCLI.py -r LelujaOriginal-Regular.ttf LelujaNew
fontforge -script ReadifyFontCLI.py -i LelujaOriginal-Italic.ttf LelujaNew
fontforge -script ReadifyFontCLI.py -b LelujaOriginal-Bold.ttf LelujaNew
fontforge -script ReadifyFontCLI.py -B LelujaOriginal-BoldItalic.ttf LelujaNew