You have the soltion.
It a repaired composition (I've no idea who the original composer was).
This is the original that sat in my book 'Mastering Chess' for 30 years.
The book is going onto Kindle (along with a new section containing loads of RHP games.)
I was not too happy with the re-printed book. It has gone through four
publishing house and 19 re-prints. Things have changed slightly.
So I did a complete re-vamp of the whole thing and computer checked every puzzle.
It found three that were a bit a 'iffy' and unclear, not bad for 40+ puzzles
composed set over 30 years ago.
Anyway back here.
The computer found that 1.Ra5 also draws so I jiggled about with it a bit
given it just one solution throwing in the Rxd3+ as a garden path.
The solution in a PGN.
The hard part, the improbable move, was allowing the promotion with a check.