thats good jonny, if those are your first attempts ever thats the closest ive seen anyone come..you have the right idea. go a little faster and like cary said, try to time it so the front wheel gives you a little pop. on a quarter like that you shouldnt have to go forward too soon, start going over the bars around 3/4 up the quarter and just tuck the shit out of it, like as tucked as you possibly can, and you should see the ground come around.
edit: oh and another thing, your tucking right off the lip..in BLT, that frontflip over a big box at rye to flat, i tucked off the lip on taht so id flip slower. couch before the jump and extend your knees while you go over the bars, then as soon as you leave the lip you gotta tuck, tucking before kind of stops the rotation