One of my saddles is a Simco - I've had it for many years now (well into the double digits). Very good saddle as it's comfortable for the horses and me and has proven quite durable. I think the rigging on it is 3/4s well. I use the saddle on horses with medium width in back and high withers. So I would recommend a Simco saddle.
For the particular one you're looking at, I think a price of $300 might be better as it doesn't have the back cinch with it nor does it have latigos (or saddle strings) for tieing stuff onto the saddle and you'd probably want both those for trail riding. As well I also think (as someone else did) that the stirrups might not be original. Otherwise, it is a good looking saddle.