User Involvement Advisors are three PWP's who are now employed by Parkinson's UK and can be contacted at national office where they are located. They are all part time so email, letter or phone in that order is the best method to contact them. I am sure if you did a search on the site you would be able to find out more.
It is the stated intention of Parkinson's UK to put people affected by Parkinson's at the heart of everything they do and to listen and respond to the needs and views of people affected by the condition. They also encourage feedback by way of complaints and compliments because our views, insight, expertise and experience will help to develop and improve a quality service by PUK for PWP's.
Right now you have a need. They may not be able to do anything more than you have done yourself already but they could be asked for research findings or input from other sources.