Google "Glass custom cut". I found a good number of places. Problem is they'll be expensive in Manhattan (unless it's Chinatown). There's a great place in Brooklyn that got me 2 pieces custom cut for $60 total: Bernie's Glass and Mirror.

Bernie's Glass & Mirror (718) 467-0649 https://maps.app.goo.gl/m6b4mZYDnJ1HYcsWA