Curiously, searching for how-tos on embedding fonts, came across this exchange.
checked out Dick Angus' test book epub. found that on my Mac browser (SeaMonkey epub viewer), the font doesn't display. opened in calibre same thing. opened it in Sigil, changed where one of the headings was centered, saved it from Sigil to diff folder as ePub, opened it in calibre. and voila, there is the font, handwriting type script.
but the font name in Sigil shows as 'elegital.ttf'.
But now will try my manuscript that way to see if I can get my fonts to show up too.