There have been both. Here is a famous example from around 1977 I believe that was broadcast on the BBC (I knew of this example but this is the first time I actually found a recording of the broadcast): https://www.baroquemusic.org/violincomparison.html . The violinist playing is Manoug Parikian, who presumably knew which instrument was which, and neither Isaac Stern nor Pinchas Zukerman (both world class soloists) nor Charles Beare (a famous luthier described as "the most esteemed authenticator in the world" by the NYTimes) could identify which violin was which.