Payment of lump sum at the end of contract

Hello together, I am currently a Marie Curie fellow in Oxford, until Feb 2018. I was wondering if you have any experience how the Universities are handling the payment of the 'lump sum' at the end of the contract. Since I get payed in Pounds but my salary was calculated in Euros, I don't know what my total salary in the end will be. Also because pound:euro changed quite significantly over time, and it may depend on when the University has received the payments from the EU (or will still receive)? I am also asking because the exchange rate set in the contract is 1:1.55 and differs quite a lot from the current rate. Thanks for any comments! Andreas