Yes Yves, looks like a logo made from Optex. Mike Yanega has the Letraset Sample in his Lined Font Identification Guide.
I believe it's not digitized ...

Ok i found the original name for the font: optex letraset 1970

And here comes my next question:

Where can I download the font?/where is it included?

or : where is it buyable?

Looks like Optex, but couldn't find a digital equivalent.

Odessa (based on Futura) and Zeppelin (based on Kabel) are similar but no matches.

I don't think it's been digitized. Well not that I know of...

In 2010, The Northern Block released a digital version called Olympik.