It is a terrible idea to do anything other than “touch-up” text editing in Acrobat, in other words, simple typo fixes and character replacements. This is especially true for documents with complex text layout. You are best advised to edit the original source document and create a new PDF file from that. Think of PDF as a Final Form File Format as opposed to an editable, source document format.
But to your specific point, Acrobat does not allow text to be edited in its original font unless the exact same font is installed on the system running Acrobat, regardless of whether that font was embedded either fully or subset in the PDF file. The fact that New Baskerville doesn't show up in the dropdown list is indicative that (1) the font is not installed on your system (New Baskerville is not a system font in neither Windows nor MacOS although MacOS does have a Baskerville font - not New Baskerville) or (2) you have the font installed but it doesn't allow for editability embedding.
Bottom line is to go back to your original document and edit there after installing the New Baskerville font on your system.
- Dov