Jb Perm
A 1×2×3 block is already solved: a full bar of three plus a two-sticker bar on the next side. Ja and Jb are mirror images.
R U R' F' R U R' U' R' F R2 U' R'13 moves · Probability 1/18 · Corners UFR↔UBR · Edges UR↔UF · Mirror: Ja Perm
Setup: apply these moves to a solved cube to reach this case
R U R2 F' R U R U' R' F R U' R'Other algorithms
Dashed keys are AUF: a U turn that lines the top layer up with this algorithm.
RU2R'U'RU2L'UR'U'LU