There has been a new development - the piano is to be auctioned tomorrow, in Jerusalem - see here
On the auction listing you will see the fabulous and extraordinary history of this piano - fabulous, because I am sure it is a fable. The whole idea of taking an 1825 wooden-framed upright (which had taken 20 years to build!) and rebuilding it in the 1860s with an iron frame seems absurd. And the idea that as originally built, it had "a more delicate sound than the pianos of those days" also seems ridiculous - in those early days pianos did have a delicate sound.
There is very little to be found about the Marchisio family, the supposed builders. But in "The Piano - an Encyclopaedia" by Robert Palmieri I found this: "The family of the three Marchisio brothers was established in 1862. Two of them, Antonino (1817-1875) and Guiseppe Enrico (1831-1903) were also distinguished pianists ... furthermore, Guiseppe Enrico invented a frame reinforced with iron, which he called "staticofone". The renowned firm of the Marchisio brothers eventually employed over one hundred people, with an output of 250-300 pianos per year, in 1875 two of the brothers died, and all operations terminated.". You will see the relevance of this if you read the "history" in the auction listing.
The 1867 date of the Paris Universal Exposition tallies pretty well with the Marchisio dates. So it seems likely to me that this is an 1860s piano, built by Marchisio, with an elaborate "art case", for display at the exhibition. All the "fabulous" aspects are just that.