An exquisite chess problem

I was shown the following problem about 40 years ago. Unfortunately, I don't know who composed it. I'll post the solution in a few days.

White to play and win

@FMDavidHLevin
Sc6 i K musi bić na a8. Zostanie tam uwięziony dopuki biały K na podejdzie bliżej. Mat S, G i K da się zrobić. Pytanie co z czarnym G który będzie przeszkadzał
zbyszek56

@zbyszek56
1. Nc6+ is indeed the right start. But if Black's bishop should safely reach the a8/h1 diagonal, White's bishop could not deliver mate along that diagonal. Therefore, White will need to eliminate that piece. How to achieve that is the crux of the problem.

The post that was quoted here has been removed

Now I don't need to post the solution. 🙂

The only clarification I'd add to the comment by duchess64 is that after 2 … Bg8 3 Be4 Bh7 4 Ne7+ K(any), White plays 5 Bd3 (essentially transposing to the 2 ... Kb7 line).

I recall how in showing us this problem, George Shrier marveled at how a simplified setting could contain so much content.