FL2 SD4 gearbox with different part numbers?

Just after some advice please from any gearbox/parts experts.

I have a 2012 FL2 SD4. I am trying to source another auto gearbox and the part number is listed as BH527000BA with land rover. It is also shown on the box too.

There seems to be more FL2s of the same model SD4 auto with the part number of BJ327000BA. I can't see any obvious difference between the two boxes. Are they the same and are they interchangeable?

I ask because the BJ327000BA seems much easier to get hold of!

Thanks alot
Kev