Engraved Or Not Engraved?

In the early 1960s Austria Post same as other postal authorities
wanted to issue colorful stamps compared to those "boring"
monochrome or bicoloured stamps.
The Austrian State Printer was looking into different options
as far as multicolour printing but hadn't decided yet which way to go.

In the meantime it was decided to contract out to a private printer
Brüder Rosenbaum Wien to print some stamps between 1963 -1966
using multicolour offset.

Here is the first example , 600 Years Tirol part of Austria
Scott 708 issued in 1963.



In 1964 Austria issued a set of 8 semi-postals to promote the
upcoming WIPA 1965 ( Vienna International Philatelic Exhibition)

Scott B306 - B313 1964



Originally it was decided to have the Brothers Rosenbaum
print the main portions in multicolour offset and then have the
Austrian National Bank Printer finish with black engraving.
As you can see the engraver's name R(udolf) TOTH is on
the bottom right but there is no engraving on these stamps.

Austria Scott B308 1964






For some reason there was a change of plans and the set was issued
just offset.
What happened? Who knows.
I would like to know did Rudolf Toth engrave any dies?
Were the plates made? Why the change and why wasn't the engraver's
name removed ?

As you can see from the snippet below, Michel Europa 1968
states they were combination print offset/recess.
Scott and the Austrian Netto Katalog show offset/litho

A few months after the WIPA set Austria issued
Stamp Day 1964.

Scott B314



This was also printed via multicolour offset by the
Brothers Rosenbaum Vienna and again the original
intention was for it to be printed via combination offset/recess.

But again no engraved portions yet the engraver's name R.TOTH
is inscribed on the lower right margin.

Here is another Brüder Rosenbaum multicolour
offset production.
I remember when I first saw it shortly after it was issued,
I thought it was one of the most beautiful stamps
I had ever seen.

Gustav Klimt's Der Kuss ( The Kiss)

Scott 727 1964