sorry I didnt reply last night, my computer crashed
I would take the dwp doc with you to the cab meeting and if you do enclose it with your appeal put a note attached to it saying "to clarify that hms and eds H/3 are the same". The mistake I made when very first applying for dla was just to include printouts of info about various medical conditions that affect me which was not what they wanted, what they want to see is how you are affected by each thing, for example it may say on an info sheet that some people have gastric problems, the dwp will view it that not everyone will have this problem who has hms so if you have gastric problems you have to explain what they are and how it impacts on your life. In my case i have got gastric problems that cause sudden bouts of upset tummy which can occur with no warning so any trips out had to be pre planned around where the toilets were. An info leaflet may state that some people will have joint pain, you need to explain how joint pain affects you, is it severe, does it make doing things/activities difficult, do you need to take pain meds and do they control the pain, do the pain meds cause any side affects. If you do manage to do an activity what will the impact be, will you be in substantial pain, very tired etc.
the other main piece of advise I can give is to join a site called benefits and work. I will put the link in for you, as amember (they have an offer at the moment, under £20 for a year) you can down load guides to help you fill in dla forms, guides on how to appeal and much more, they also have a forum. I used these guides for my esa and dla awards after failing my first dla application, the giudes support you one question at a time explaining what you need to be thinking about with your answers, they make it easier to understand what the dla fom is actually asking, (I didnt put enough info in my form first time). the other thing to know is that you can re apply straight away with a new claim using the guides which might give you a better case rather than go to tribunal which can take a year. I re applied straight away and was awarded high rate mobility 8 weeks later, that was over a year ago and I have since had to renew, I had gone down hill quite a lot since then (complex problems) and now also have a care award too.
hope this helps. and here is the B&W link; http://www.benefitsandwork.co.uk/