Two-movers by the eminent British composer Comins Mansfield never fail to impress. White to play and mate in 2. Find the key.

What if Black captures on f1? 1. Rf1 gxf1=Q - How does White finish it off?

What if Black captures on f1 and underpromotes the pawn to a knight? 1. Rf1 gxf1=N - How does White finish off?

1. Rf1 gxh1=N - How does White finish off?

1. Rf1 g1=Q - How does White end the game?

1. Rf1 Rxg4 - How does White finish off?

1. Rf1 Nh5 - How does White finish off?