The one on the left is a heavy piece of glass from one of those molds. No blots can be seen on this one. Brookfield got and used BGMCo molds in 1897.

The on eon the right is a different style of CD 164 Brookfield - beautiful yelow-apple-greenishy-like color. This gem glows when sunlight hits it. I have not see another in this nice of a color (likely overlooked and out there), although I have seen at least one in more of a lime color (less yellow tint).

The one on the right was probably made at the Brooklyn, NY before all insulator production was moved to the Old Bridge, New Jersey plant for production starting in September of 1906. Most Old Bridge glass is much darker (think CD 152 Brookfield).

Microsoft Moment alert! The original pic has a white backdrop, but when I uploaded it, its now black!