Polish My Memoir Manuscript

I have a biography-style nonfiction manuscript just under 50,000 words that now needs a meticulous grammar-and-punctuation overhaul. The story structure, pacing, and voice are already set; what I need... (Budget: £18 - £36 GBP, Jobs: Biography Writing, Copy Editing, Editing, English Grammar, English Spelling, Language Tutoring, Proofreading, Writing)