I finally set myself the challenge of searching for Loudon's original catalogue. I'm sure it's out there somewhere, but no luck. Instead I found the list within a copy of a gardening magazine from 1840, including map, which I'm just about to print out and hopefully follow it to see which are still there from the original landscaping. Obviously, not all the trees are still there, they got rid of 100 trees in the past couple of years after securing lottery funding to restore the park.
I have to say, not only yay to Google for making all these old books and magazines digital, but it's not quite as laborious a read as I expected. In fact, it reminds me a lot of forums in places.
Here's a snippet about how to store your carrots -
