Hi Ben
If you can get a more up-to-date assessment that more accurately reflects your current skills, it could help - but be aware that it's not a guarantee that the PIP decision will be 'more accurate'. PIP assessors are notorious for ignoring evidence from hospital consultants from all disciplines, thinking they know better about what a claimant can or cannot do in terms of the PIP criteria. If you can get the report, do so; otherwise, you will have to rely on telling them how much your health has deteriorated.
As you are not familiar with PIP assessments, make sure you have a look at the Guide to PIP Claims and reviews to see what type of questions you could be asked at an assessment.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
