Logic Masters Deutschland e.V.

This puzzle was created for Scojo's weekly setting prompt featuring "Skyscrapers" and "Indexers".
I hope you enjoy solving it!

To solve online, click here or on the image below.

Rules

Normal sudoku rules: Place the digits 1 to 9 in each Row, Column, and 3X3 box.

159: Digits in column 1 indicate the column in which the digit 1 appears in that row (e.g. if R2C1 is a 4, R2C4 is a 1). The same applies to columns 5 and 9, with the digits 5 and 9 respectively.

Skyscrapers: Each digit in the grid represents a skyscraper of the corresponding height. Clues outside the grid indicate how many buildings can be seen from that direction, where higher buildings block the visibility of lower buildings.

Cipher: Each letter represents a different digit from 1 to 9. The same letter always represents the same digit.