Since writing the last missive, I have noted two more examples.

There is, or was, one in the Musical Museum, Brentford. There is a
recording of it on their cassette recorded in 1994. Presumably it is
still there, though I haven't visited for several years to check.
Example 4 presumably.

There is, or was, one in the Collection Anezo-Bouilhol, location not
mentioned on the CD that I have (mastered in 1977!), but put out by
Disques Pierre Verany of Aix-en-Provence, France, so presumably the
collection is in that area. Example 5 if it is still there.

Thanks.

David Evans, Hampshire, UK.