I found a file some time ago at a local store here in Twin Falls, Id., with the perfect angle to cut shallow Vs, I bought two of them, wish I had bought all of them..they are a shallow V at just the right angle, and are smooth on the top side...Never seen them before or since....

It makes no difference what size the sight is, why would it unless or course it was wider than the file, but that would be an easy adjustment.