[Superscope]

Peter,

Surprisingly, part of the answer may already be in this Multimeter Survey.

We currently have Two Model 7's from 1936.
My one, and One from Forum Member Andy265, who only posted once in 2009 and never came back.
At least we know the older Switch design was in use.

We don't have any from 1937.
Now there's a chalenge if anybody wants to take it up!

We only have One from 1938, by Forum Member Pelham18 in 2017, but he only posted Four Times, (all on the Multimeter Survey)
and he never came back again.

However, the good news is, he did post a Photo of his 758-1616 Model 7.
You can find it on page 72, post # 1427 third attachment.

Looking carefully at the Photo, it is difficult to see, but I think it is definately the old style Switch being used.
What do you think?

So it would appear the old Style Switches were still in use up to 1938.

We have Six from 1939 recorded, and Five of them are from currently active Forum Members.
I don't wish to reveal which Forum Members have which Meters, but if they wish to
jump in at this point all the better, but at least One has mentioned the Switches are
the New familiar Modern Style.

From this, I think it is probably safe to say, the New Style Switch appeared in 1939, (maybe late 1938).
Possibly it co-insided with the launch of the Model 40.



Ian