4x4 Rear Differential Advice

Hi all,

Forgive me if this has already been asked in the past, but I'm going around in circles trying to figure out which rear diff replacement to buy.

I have a 2016 Octavia vRS 4x4 which had a failure in the bearings on the diff. I had the diff rebuilt by a VAG specialist about 18 months ago. Since then, I've moved 150 miles from said specialist and it has failed again.

It makes a grinding noise, shakes at 70mph and I've discovered there's oil/fluid that has blown backwards from the diff.

Rather than messing about taking the car back on a 150 mile trip and them worming out of any liability, I've decided it's just easier to swap the diff out with a different unit.

I know the part number is 0CQ525010 but how do I know which revision letter to go for? The pic I managed to get from underneath the car only shows the part number above but no additional letters.

Thanks in advance.

Andy