Fitting new body cappings

I will be starting to fit new body cappings to my 90 starting this weekend. Hoping to have it done in 2 days so I just want to run a few things past our experienced members.... and any other advice is greatfully recieved.

I want to have all the 'bits' in hand if possible... the rubber seals listed below are a bit confusing to a novice like myself. Also, the size and type of nuts and bolts, screws and washers I should have ready. I have a selection of sizes of blind rivets so hope I am okay on that bit.
I am happy to replace all seals.... I will use a clear, flexible sealant when required.
The major seals to replace seems to be on top of the body capping. From the inside it is about 20mm thick. Is it called 'hard top seal rubber lower' part No 333487?

Looking at this website as a guide with the above number
Defender 1985>: Body/Fittings: Seals/Channels | parts and spares | www.lrseries.com | L. R. Series

Sorry this is a bit long winded....

Can anyone suggest a names of the seals I should replace or an assortment of nuts bolts etc I should have in hand?

Attached pic is part of the badly rusted body capping.. replacements are one piece thanks to Ian Notts

Thanks for looking