Lord's gives 35 entries under "Dennis Sandole", as well as 1 for Dennis Sandoli and 2 for Danny Sandoli. It's pretty clear from context that they are variant spellings, and not different people.
Early Dennis Sandole Sessions/Compositions
Lord's discography lists 21 airshots and recording sessions with the Tommy Dorsey band between and 10 Feb 1943 and 1 May 1944.
There are 4 sessions listed with Boyd Raeburn (15 May thru 30 June 1944)
and 4 with Charlie Barnet (23 Mar thru 20 May 1946).
Sandole's mysterious Fantasy album "Compositions and Arrangements For Guitar" [Fantasy F 3251, 1958] is not listed, and I still have no further information about that one.
Charlie Ventura co-wrote "High on an Open Mic" with Sandole, and recorded it seven times between 1947 and 1977. (Begins at 21:12 in the video below.)
Variants
Danny Sandoli is credited on two additional airshots with the Tommy Dorsey band, one from 11 Oct 1943 and one from an unknown date, but released on a V Disc, so clearly sometime during WWII. (The Lord's reference numbers are [D5935-16] and [D5932-16] respectively.)
[[Note: Discogs user gurunet posted an entry for the first, but it doesn't appear to match the info provided by Lord's. Maybe someone can help clarify this.]]
Dennis Sandoli is credited on a 16 July 1942 studio date with Ray McKinley, which resulted in 8 cuts, spread across several releases. (Lord's ref [M4725-16].) Four of these were compiled by YouTube user Ralf Siebert:
Consistent with the style of the day, Sandole's playing is more "felt" than "heard".
"Sandoli" was a fairly common misspelling of Dennis' last name, and can be found in print numerous times throughout the 50's. Here's an example from the Wilmington News Journal, 2 Feb 1956 (p 31):
The variation Denny Sandole can be found in print occasionally, as in this ad from the Philadelphia Inquirer, 13 Sep 1948 (p 19):
Lastly, I came across Dionisio Sandole, which appeared in the Baltimore Sun on 26 Feb 1955 (p 3):
I include all this with the hope of aiding future researchers in finding out more about this important figure from jazz history.