I find Spring Perches in the Lang's Catalog, left and right, for Model T, 1919-1927, but nothing for 1909-1912 (or maybe 1919). Is a spring perch the same for all years of Model T?
I understand that difference, now that you mention it, but do the early and later perches connect to the Springs, in the same way? Steven Lang told me that he didn't think that many are still using the early perches and he really didn't know if anyone was manufacturing them, anymore.
Unless you are building for show, you might think about going with the newer style. They support the axle better. If you go with the early style, would suggest adding the brace that was sold back in the day that mounted to the underside of the front axle.
Yes the spring mounts the same all years but the style of oilers or how the shackles were oiled did change and spring style as well.