Austria #649 Proof Signed By Artist Not Designer?

The stamp is designed Ranzoni but signed by the Austrian artist and graphic designer Welenofsky ? Was Welenofsky on the selection committee for Austrian stamp designs or why else would he sign this proof?
Any help would be most welcome as I want to exhibit this item under harps in my exhibit .

My guess, is that Welenofsky was the artist and Ranzoni was the engraver.

This is not a proof. The picture does not have the precise lines of an engraving. Ranzoni is both designer and engraver, as indicated by his inscription in the center of the bottom margin. I don't know the full details of these after just a few minutes of searching, but it appears many souvenir 1st Day Cards were created with Welenofsky recreating the stamp design in a hand-drawn picture.

It seems others are also confused by these, as the Stamps On Stamps Collectors Club journal called one the original artwork for a stamp -- https://www.stampsonstamps.org/SOSS...Signal18.pdf -- , and Cherrystone Auctions had an auction lot of these they described as die proofs. https://www.cherrystoneauctions.com...ntry=AUSTRIA

I've never heard of hand-drawn pictures being used as die proofs.

As I said, though, I only did a few minutes worth of searching, so I could be completely off base.

Google search: https://www.google.com/search?q=pos...e=UTF-8#ip=1

This is an essay by Welenofsky.

https://www.stampcircuit.com/de/sta...sonderheiten

The essay in the same design pops up on Ebay.

https://www.ebay.de/itm/175724219235

From what I see using Google, they tend to have a signature in blue ink and are on a cream-coloured paper.
It raises the question whether OP's item is a reproduction of the original with the signature in the same black ink as the stamp image and on white paper.

Thanks for the help from the three of you I guess a will call it an essay reproduction sighed by the Artist. Mine is on cream colored paper signed in blue ink but doesn't have the real stamp attached . I will display it with a stamp at the bottom using layered protection so no sticking will be required Didn't pay a great deal for this and reduced the postage costs alot. So I still don't own a signed stringed musical instrument proof . The search goes on

I am not famiiar with these, but in my mind, the term "essay" relates more closely to trial designs and iterations in the process of reaching a final design, sample designs, rough ideas, etc.
Rather than this piece which seems to be made very close to the time of issue and more closely resembles a cachet, not for an envelope, but for a philatelic card of some sort. Without knowing more, I would be very hesitant to call it an essay or put it in any exhibit without a more exacting explanation.

We are talking a stamp from a German-speaking country. An essay can also be a study of something that exists. In this case, 'essay' would mean 'artist's impression,' i.e. an essay of a design rather than for a design.

The OP is posting from Canada, so these nuances should be very clear in any write-up.

I am from the Netherlands. I do not write up my GB, Ireland, or Spain collections in Dutch.

Ah, but most Dutch people speak better English than the English themselves.