If you measure the appliance freezer door height and divide it into your height of 177 that will give you the split. You are going to struggle to replace it like for like as the width is not the standard 540mm.
If you go through caravan/ mobile home suppliers you will be looking at a high price as it’s a niche product. The only other thing you could consider would be to put a freestanding 55cm wide fridge freezer in there like a Hotpoint HBD5517 however you will lose the “integrated look. “