The First Improvised Piano Solo on a Jazz Record?

According to Arthur Schutt's obituary in the Feb 2, 1965 isssue of the New York Times,

"His [Schutt's] chorus on Paul Specht's recording of "All Muddled Up" in 1922 is thought to be the first improvised paino solo ever recorded."

The recording can be heard on youtube,

http://www.youtube.com/watch?v=zg772soHXTs

According to Rust, "All Muddled-up" was recorded on Oct 11, 1922 by Paul Specht's Society Serenaders, .Frank Guarente-Donald Lindley-t/Ray Stilwell-tb/Harold Saliers-cl-bcl-as/Johnny ODonnell-cl-as/Frank Smith-cl-ts/Al Monguin-bsx-a/Arthur Schutt-p/Russell Deppe-bj/Joe Tarto-bb/Chauncey Morehouse-d. (three connections to Bix). The recording was issued on Col A-3740. Here is an image from Dave Garrick's terrific jazz age website.

According to

http://www.mgthomas.co.uk/dancebands/American%20Visitors/Pages/Paul%20Specht.htm

"The Specht band had come over here to play at the opening of the new Lyons Corner House in <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Coventry St, London, and this establishment duly opened on May 30th, 1923. Variety for June 7th reported Paul Specht and his band opened at Lyons Cornerhouse (sic) Restaurant May 30 and were enthusiastically received. The restaurant has been packed continuously from morning until closing hour since the orchestra opened. Variety further reported on July 19thPaul Specht s band did 27 minutes in the vaudeville programme Monday at the Alhambra. Its selections rangedfrom pops to classics. The band got eight recalls and was a big success.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

Although some recordings were made in London by the full orchestra, the title All Muddled Up was actually cut in America the previous year. Messrs. Lyons had a quantity of single-sided records made of this title. Bearing a special Lyons Corner House label, these were presumably on sale at the Corner House as souvenirs."

I believe the source for the information in the obituary about the first improvised solo comes from the Biographical Encyclopedia of Jazz by Leonard Feather and Ira Gintler. Do you think that the solo is improvised? How can one tell?

Albert