tribunal appeal

I asked for an MR for my PIP but the decision was unchanged so now I'm going to appeal to a tribunal. I've written my appeal and completed the SSCS1 form. I wanted some advice about sending evidence. I sent letters from my G.P, physio and psychologist with the MR, but obviously it was ignored. I'm now thinking of getting another letter from my G.P basically re-enforcing what everyone says. Should I send this new letter with the SSCS1 form or shall I wait for the date of the hearing and send it then?
Any advice will be helpful.

Thank you for your reply. Do I need to send the evidence, that i originally sent to the dwp, to the tribunal, or will the tribunal have access to it?

i finally had my tribunal today after a long year and I've won. however i'm not entirely happy. i have been awarded standard rate for the care component. i feel I'm entitled to the high rate. i was very nervous and feel i didn't give the proper detailed answers to their questions. they concentrated more on the bathing and washing activity and, i feel, ignored the preparing food activity. cooking food is a daily activity which someone does for me every day as i can't cook due to my disability. whereas bathing or washing is one/two times a week task.

they did ask me if their was something I'd like to talk about, but like i said i was so nervous i forgot to mention this. I've only been awarded 2 points for the preparing food activity and feel its unfair. but i don't know what to do? can i appeal? should i appeal?

any advice would be grateful.