Let me have a rummage, I've a box of lenses and assorted optics I salvaged from the skip after the local technical college cleared the labs a couple of years ago. It's a double-convex lens you're looking for? Although any I have would be uncoated, and I think that part of the video is just playing a reflection off the coating.
Otherwise just break for parts a cheap pair of binoculars from a charity shop, carboot or eBay.. fieldglasses is just a synonym for binoculars.