Howdy Pards!
I don't have one of each to "trial and error."
As shared though, generally "Italian" repro stuff is only "simiilar" and not exactly so it will NOT "pop in." NUG, the Italians make things larger and bulkier than oriignal. That can be a small "plus" as "oversized" wood can be taken down to fit. However, IMHO, the is still a great danger of the mortising for the frame and the mortiising for the buttplate may be off enough to leave gaps requiring advanced skillful magic cosmetic splicing or filling (which IMHO is rarely invisible).
Plus, if it is a factor or concern, the originals are Pennsylvania grown American Black Walnut which is not the same color range, grain and texture pattern, or density as the Northern Italian "Hardwood" the repro Italian stock wood is...
I have a great deal of experience modifying Italiian Civil War repro Springfields and Enfields, including trying to swap "more authentic" and actual reproductions of original or actual original parts and they NEVER "drop in." Some cannot be "made" to fit at all....
At the rate of what we get for the U.S. Dollar versus the Euro these days, Italian parts can be pricey any more. Even if one orders a stock and visually determines it does not work or cannot be made to work0- one is still out the postage costs and time to return it.
As shared, I would try Dixie (but remember these are not "drop in" replacement stocks, and typically are 85%-90% mortised and shaped.... and IMHO, Romano may be the an alternative worth looking into..
Mick Archer