Spenser’s poetry is always printed in the original spelling and punctuation (although a few of the most confusing punctuation marks have been altered in the present text) , since it was a deliberate choice on Spenser’s part that his language should seem antique.
(A modern reader who read Shakespeare or the King James version ofter Bible in the original spelling would not find as much difference in Spenser, but he would find some.)
Furthermore, Spenser uses his spelling to suggest rhymes to the eye, sometimes to suggest etymologies, often incorrectly. The fact that Spenser’s spelling is inconsistent is simply typical of his time; in the 16th century a man varied the spelling of even his name to suit convenience or a whim.