Hi Grahammylo
Your question is outside the remit of the forum but I will try and answer as best I can from the details in your post.
Your joint claim does not end but your state pension will be taken into account £ for £. I do not believe there will be any difference in your income, what should happen is that your wife will get a UC allowance based on what you already receive less your state pension and any other pension you may receive.
I would advise you to seek help from your local Welfare Rights Organisation;
advicelocal.uk they will be able to take all your circumstances into account to give you an accurate picture.
Gary