Hi Chester64
Send a copy of your additional evidence to the DWP, send a copy to the address of the assessment provider (which will be on the letter - if you already have an assessment date), and take a copy along with you to the assessment itself and ask the assessor to read it before the assessment starts. Don't forget to put name and NI number on each side of additional sheets.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems