I have edited to remove (unknown completions) from this RG on the following basis:
The Sussmyr completions were the standard practice until the following book was published:
Alan Tyson, Mozart: Studies of the Autograph Scores, Cambridge, MA: Harvard University Press, 1987.
As these recording were made in 1961, in the absence of any evidence to the contrary, we can safely assume that they followed standard practice for those times. And used the Sussmyr completions.
I suspect that this also explains why the (Sussmyr completions) and (unknown completions) are grouped in the same work - before 1987 (AIUI) everyone did the Sussmyr completions without being aware of it, and therefore made no comment or clarification.
And after the Sussmyr completions had been recognised it became accepted practice to state what completions were used.
However I think this reasoning (if indeed I am correct) needs to be made explicit on the “(Süßmayr completions) and (unknown completions)” and perhaps limited to ??pre-1990? recordings as I see the possibility of a poorly documented recent release using non-Sussmyr completions but being tagged with this Süßmayr/unknown work.
At Concerto for French Horn no. 1 in D major, K. 386b / KV 412: I. Allegro I have added the following annotation:
Caution with poorly documented recordings suggested.
This work is a (catch-all for unknown completions) and for the (Süßmayr completion).
The Süßmayr completions were the standard practice until the following book was published:
author:Alan Tyson, Mozart: Studies of the Autograph Scores, Cambridge, MA: Harvard University Press, 1987.
For releases made prior to 1987, in the absence of any evidence to the contrary, we can safely assume that they followed standard practice for those times. And used the Sussmyr completions.
However for releases between 1987 and the date when Tyson’ discoveries became universally accepted, for releases whose date is unknown and possibly after 1987, and for poorly documented post-1987 releases there is the possibility that an unknown completion is not a Süßmayr completion.
Using this work for such releases could create erroneous data.