Unknown 5: Unknown Alexei film

Unknown Alexei film, series or documentary
-Year: ?
-Year in film: 1916 ?
-Country: ?
-Who in clothing: Alexei ? ~10 ys, sailor suit
-Who in clothing 2: maybe other clothing/uniform
-Available on DVD: ?
-I own: no
-Clothing occurrence: low ?
-Rating: 4/10 ?
-Rating: ****
-Comment: Young Alexei (?) in a medium blue sailor suit.

This is from a fan video called Tsarevich Alexei Romanav - The Story of My Life. It is a collage of different Alexei feature films and also some real footage (b&w). I thought, I already had entries of all Alexei films (which are available) but I haven't noticed this scene/this actor. The boy looks maybe even younger than in most films (11 yo), and is definitely not 13, and the collar looks rather medium blue also unlike most other films. It's not from a pic but a moving scene playing with the dog. Maybe it's a different (Russian) film, but might also be from a movie I have. I haven't checked all films completely, so it's possible. The image quality is a bit poor, maybe from a VHS source. Maybe it's even a self-made clip.

I can't say much more about it. The collar flap is quite long and looks good, but the boy looks very young.

Rating 4 for now. There are definitely better Alexei films like Anastasia: The Mystery of Anna (rating 7).