This is a really fine machine. Made in West Germany (yes, at a time when there were two countries called Germany!) and imported to Mexico. Spanish keyboard. Fully original, down to the all-metal ribbon spools. This machine was serviced recently by a professional technician and is in full working order. And it still has its original rigid carrying case!
Your picture made me realize that SM3/4s may have some colour / geographical relationship; I have not yet seen this grey colour in Australia. My wild estimate is that 99% here are grey-green!
I've seen this model around here in this shade of grey and also in an olive-ish green, also krinckle finish. I've seen pictures of it in a dark maroon, too; but I still have to see one of those in the metal.