Very few European springers had safeties in the old days - after all, a single-shot mechanism that can be un-cocked is really pretty safe already when you think about it.
The 35 has been made since the early 1950’s. It was the first HW model to get a safety, in the late 70’s IIRC. The first safely was a little different, too, it had a button on the left side but it did not pass all the way through the receiver. A few years later the 35 got the safety that they are still using, i.e., with the red indicator on the right side.