If you are going with the idea that Ben’s first saber was Anakin’s, maybe in the TFA Force vision, you could add the saber somewhere on the ground. Perhaps it could be laying right in front of Rey’s face when she falls in the dirt near Luke and R2.
Also, some other general suggestions that might help with the flow of the shots, I wonder if you could do a match cut of R2 in the rain to a shot of dormant R2 in the Resistance base. Then, you could create a fake whip pan (just like what was used between the shots of Rey and Luke/R2), from dormant R2 to Leia handing Maz the saber. The extra shot might help emphasize the idea that R2 was the bridge between Luke and Leia’s possession of the saber. I wonder if you could also use that whip pan effect to exclusively use that shot of Luke from the teaser, that way you don’t have to try and match the two separate shots.