Identification: What is this please?

I've had this plant since infancy, 6 years. It's now 4' high and 6' wide, leaves are about 12" long by 16" wide. It has taken over my office and I must list it! Similar to a Split Leaf Philodendron, but doesn't look the same as any pictures I find.

 

Philodendron bipinnatifidum, (Or P. pinnatifidum depending who you read)

http://www.thegardenhelper.com/pixpg/selloumpix.html

HTH
Chris

 

Thank you!