Apparently not, Guest above, as I've just been shown a photo of him holding what appears to be an English tenor-treble. However, the paragraph above states:

" ... he gave a duet of exceeding beauty upon the piano and the concertina. He swept the keys of the former with his left hand and manipulated the concertina with his right"

This would seem to indicate a duet concertina rather than an English, as this would seem an unlikely feat on the latter.