CD, I recently got a 15-96 in a straight leg treadle just like yours. I think it's a 1956 model 15. Did they make the same straight leg treadle cabinet/irons for all those years? You say yours in 1940s...so, over 10 years? Thanks.
I am also planning to put my 66-1 brown lotus decals in this same treadle base, swapping out the 15.