What an amazing set of reply's.
I emailed LZ Patterns and this is the reply;
"I like 2mm leather very much, but actually 2.5mm leather is OK too, 1.8mm is OK too LOL
This is the character of vegetable tanned leather, )"
As the response was so quick I decided to by the pattern.
There are not any instructions, but having seen the pattern, DANDTON's post and a careful watch of Nigel's video it looks pretty straight forward.
I might even be brave enough to post some pictures here if it turns out half decent.