The way you treat a letter printed with an arrow above it (representing a vector) depends on the context and on the style used in the rest of the text. If the letter is printed in bold type, the typeform has mathematical meaning and so is retained. In such a case, the arrow is omitted. NC §35.b says this: "When both boldface type and arrows of uniform construction are used in conjunction to represent vectors, the arrows themselves must be omitted from the transcription unless the author calls special attention to them as a notation device, but a transcriber's note must be included indicating their presence in the ink print copy."
If the vector letter is not printed in bold, then the arrow is transcribed as a modifier above the letter, as you have done. However, read the surrounding text to determine if this arrowhead style has specific meaning. The half-barb is often a printer's style and may have no mathematical meaning. If ALL of the vector notation in your book shows the half-barbed arrowhead, you may change the arrow to the 2-cell contracted form. This will relieve both reader and transcriber. The reader should be told in a transcriber's note that the arrows in print use the upper-barb style.
Thank you for your question.