Landing Gear Fork dimensions

[dancetothedrummersbeat]

Hi all. I bought a cheap complete bmx off ebay last week which will be stripped & re-built as a custom build (wait and see!). It came with landing gear type forks (cheap copies of course!). The forks are very chunky, with the tubing being 30mm in diameter (outside edge to outside edge), with a circumfrence of 100mm.  The forks are threaded 1". Can anyone tell me the width and circumfrence of genuine landing gear forks as a comparison? Pics below. Thanks for your help!