I needed an alto oboe. According to Yamaha, the closest modern equivalent would be the cor anglais. However, in our instrument list, the cor anglais is listed as being the same instrument as the English horn:

https://musicbrainz.org/instrument/3590521b-8c97-4f4b-b1bb-5f68d3663d8a

"The cor anglais (UK: , US: or original French: [kɔʁ ɑ̃ɡlɛ]; plural: cors anglais) or English horn in North America, is a double-reed woodwind instrument in the oboe family. It is approximately one and a half times the length of an oboe."

According to Yamaha, it isn't:

https://www.yamaha.com/en/musical_instrument_guide/oboe/trivia/trivia010.html

"From before the Baroque era through the classical period, the style of the oboe family of bass instruments was not established, and those instruments took a variety of forms and had a variety of names. At that time, an instrument equivalent to today's cor anglais (an F woodwind) was called the alto oboe. In older scores, the sounding pitch of the alto oboe is sometimes noted using an alto clef (as with a viola).

The English horn is another oboe relative in the alto range.+ The angle at which the pipe tapers is slightly different than that of the oboe, and the English horn is never referred to as an alto oboe.+ Comparing tones at the same pitch, the English horn produces notes that are more nasal and softer. Oboists also play the English horn, but it can be considered a separate instrument with a different feeling."

Simplest solution woud be to split out the cor anglais from the English horn, and to add 'alto oboe' as an alias to the new cor anglais entry. The Wikidata entry for the cor anglais is https://www.wikidata.org/wiki/Q185041