PG
If your limitations have changed since the Decision was made then this change would be legally excluded from any appeal that you might make.
You can only appeal based on how you were when the Decision was made, so, you will have to decide what is the better option for you.
You can appeal and make a new claim but doing this will create what is called a Closed Decision in regard to the Tribunal, this means that whatever Decision the panel reaches it will only be in effect until the date of the new claim, after this the Decision from the new claim will be used.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems