A 3m bredli would have a fair bit of age on it, given that growth slows dramatically after about 3 years. I believe the 2.5-3m pythons we see occasionally around here are big old girls that are probably well in excess of 20-25 years old. It's an interesting question actually, and I'd be interested to know how many years some of the members here, or someone known to them, has had their oldest snakes. I'm guessing that there would be VERY few in the 20+ year group.
Jamie