Rushton, your point is well taken; Ravel orchestrated the music, and he is not Russian. However, the importance of the orchestrator (even Ravel), and certainly his/her nationality, must take a back seat to the composer's. The orchestration of any work does not usually determine the music's meaning at a level nearly as basic as the composition itself; regardless of what instrument(s) the music was composed for. IOW, an Irish reel orchestrated for large orchestra is still an Irish reel. I am less concerned about the nationality of the orchestra than I am about the nationality of the conductor; although the orchestra's nationality can play a significant role in capturing (or not) the appropriate flavor of any composition. Clearly, many compositions can be done justice by performers/interpreters of a nationality other than the composer's; there are many recorded examples of that. But I will offer a personal experience to describe what I am referring to:
I am an orchestral saxophonist, and as I am sure you know, the saxophone solo in "The Old Castle" is probably the best known orchestral saxophone solo in the literature; with the posssible exception of the solos in "Bolero" (also Ravel). I have played "The Old Castle" more times than I can remember; and for many different conductors. I thought I knew and understood "Pictures" very well until I had the pleasure of playing it under Gergiev two years ago. It was almost like it was different music. He had an exceptionally deep understanding of the music, and ability to convey what he wanted, and continually referred to what it was he wanted as being tied to the music's ethnicity. I found it fascinating, and one of my most memorable experiences as a player.
The Reiner recording is also fantastic. Hard to beat the Chicago brass section for sheer power. But, if you have the opportunity, listen to how Gergiev brings out the dissonances in the brass chords; what he refers to as the "spiciness" of the chords. I found it thrilling, and it gave the music a flavor that I had not been aware it had. Was his interpretation the result of his being Russian? I don't know. But I don't think it is too far-fetched to think that it had a role.