An article about WC butterfly swords per my lineage's history.
Article #6
Article in video form with some accompanying pics of what the article is referring to:
I've read some of that somewhere before.
I think the main problem with it is that the 4 types of blades mentioned do not tally with photos of actual dao available. What then is it talking about?
It also makes the shaolin connection which to me is always a bit of a red flag, given that most of these stories were made uip in HK in the 20th C. because that is what the punters wanted to hear.