Possibly Rohn or Delhi, but who can say?
They put lots of datasheets on their websites so you should be able to look through them and figure it out - or at least know what it isn't.
I have analyzed a number of free-standing lattice towers for a ~3KW, 14-ft diameter turbine that I want to build. I always found them lacking, even though they had 36" space between legs at the base. Sure if I compromise, and use only 50 feet (but I already have a 45-ft tower) or put guy wires on (but my mono-pole tower already has guy wires) then I can make the math work out fine. But there would be no point of putting a big turbine on a short tower, as you know. Every time, I find that the legs are not sturdy enough for the gyroscopic effects of the turbine yawing, if I count the thrust force on the blades and there is a weight of ice at the same time. The bent-angle legs will buckle and collapse.
If the legs of your tower are tubes, not angles, then it's worth pursuing a litter farther; you may have something.
But as said already, anything that looks like a TV antenna tower is not fit for a wind turbine. They make great anemometer / weather station masts through! If you want to use it for that I can tell you a little more.