Recommendations and quotes wanted to replace small landing window and pull mechanism

Hello,

Looking for recommendations to replace / repair small very damaged window on landing. Access via ladder on the landing in a house located on Haringay ladder.

Acorn are coming to quote for the other rotten sash windows later in the month but this small one is completely damaged we're trying to get it looked at asap.

It opens and closes with a rope pull mechanism. Glass is falling out and frame rotten so the window doesn't close properly. Mechanism to open and shut via pully. See photos.

Would really appreciate recommendations for reliable, professional company that will do a good job so we can get quotes.

Thanks