Beloved lamp, Czech crystal?

This lamp was given to me by my gandmother and I would like to know more about it? I was always told it was Czech crystal and "antique." It does seem like an example of cut crystal from the Czech. The colored glass is ruby red, the lamp dates back at least to the 1920s, maybe older, and it is HEAVY. From base to filial is almost 36". My husband wants to insure it before we move, but I have no idea what it might be worth.