Hi nashy
I know your post was from last year, but just in case you still need the information regarding where to obtain inventories, I have got many probate inventories from the West Sussex Records Office in chichester where they are held on microfilm. If you send them an email quoting the ref no. you have, they will send you a price for photocopying, here is their email address.
records.office@westsussex.gov.uk The advice that Roy G gave is for a copy of the probate of the will which is completely different from the inventories, so it may have sent you in the wrong direction

The inventories make fascinating reading. Hope this helps!
Karen