Is there anyway to turn a ".wfn" font file back into a "font." file to edit it with the SCI font editor?
I don't know a thing about the .wfn format, but what I know, if it helps you, is that you can rename .fon or .fnt files to .ttf and they work, if you import them with the same size as you saved them...
No, currently there is no way to reverse WFN files back into SCI Fonts, I'm afraid.
Making a converter utility is on my to-do list, it's just very low priority.