Here are the first 8 add-ons, these are all responses to ideas and feedback so if you have any suggestions please let me know.

 There are 5 sets of these walkways.

Set One 3 single walkways, 2 double walkways, 1 triple walkway and 2 entrances

Set Two 1 triple walkway and 2 quad walkways

Set Three, 1 corner, 1 T junction and Crossroads

Set Four, 1 Bridge section and 2 End sections

set Five, 4 end sections

 These sets are £5 each or 4 for £15