You should be able to bring up the express sights that Brownell's sells. I used one long ago, and last time I looked, they were still listed in the catalog. Seems to me the sight alone is around $100.00 in the White, with the base for a round barrel running another $50.00 or so. Prices might be higher today as this was some time ago. I'd try googling English+Express+Sights and see what you get.