Here is a pic. Do you think it's a filibusta or a robusta? (Yard stick in tub for perspective)
Here is a link that might be useful:
Well, I'm hardly an expert, and I've never had the hybrid, although I have had both CA and Mexican fans. To me, the narrow leaf blades and the overall "look" are more typical of the CA fan, so I think there is a strong possibility it could be the hybrid. My 2 cent opinion, probably worth about 0 cents.
I agree with Denninmi, it looks like a Filibusta with features more like a Filifera. Definitely not a Robusta. I have 2 Filibustas, and both have more reddish trunks. That palm you have has the color trunk of my Filifera. In addition, at the base of the petioles, Robusta has red, yours has green.
Can you rule out pure filifera?