Including non-Google fonts with Theme Manager

I need to include a non-standard/non-Google font. As far as I can see, this is not possible. I tried editing the font section at the beginning of the bootstrap css file, but it was overwritten when I saved the file - or a least when I made a change in Theme Manager. This is not very surprising given a font is still specified in the Fonts list in Theme Manager.

I’ve included the font another way, but as it is, a redundant font is also included, in the Bootstrap css file. Is there a way round this?