Anyone know what oil seals the mnr reverse box uses as mine is leaking from both flanges .

I think MNR no longer sell them, but obviously would be a good starting point.
Your other alternative would be to remove the seals usually they have a cross reference number.
Allseals should be able to match it up, I sent them a seal from a very old trailer a few years ago and they marched it up and posted me out some new seals, cheap as well.

https://www.allseals.co.uk/

[Edited on 21/4/21 by PAUL FISHER]