I've got a Semi-Pro that I bought new in Nov '79 for about $375. Can't recall if it was on sale, Year-end model, a new '80 model or what-not. I just remember that it fit me and was made of steel and I could afford it. All those factors narrowed my choice down to one bike that afternoon at the LBS. A SR Semi-Pro 12 speed in pink! (Actually a smokey, dusty rose kind of pink in metallic) Over the years I've often thought to paint it another color, but now I love its graceful beauty. Plus, I get lots of compliments over its original condition.
It has all Shimano 600 (Arabesque style) with a seat post, stem & bars by SR. The pedals are quill style MKT with toe clips. Rims are Araya 27x1.25, but my brakes do not have "safety" levers like yours.
I always thought that this bike was made by the same Japanese company "SR" (Sakae-Ringyo) that makes stems, cranks, etc. But I was recently told by someone who was a dealer at the time that SR bikes were made at the plant in Mexico by a company that took over after Windsor went away.
My bike has no stickers or stampings that say where it's made.
I'll attempt to take/post pics later.