Since you had possession of it and it reads like you skirted a CA law buy a new lower (can be found for cheap now), move all the parts over, and destroy the original lower. Or just sell the parts except the lower. Unless you can prove you moved out of CA before the law passed and received it from the original buyer before that date it could come back to haunt one of you if it ends up in the system again. That is a long shot but possible. Honestly it just isn't worth the risk (though very low) when a new lower can be had for $40.