Thanx Stik, no I was more wondering about the Y-harnass than the lapstraps. Even the lapstraps on the kit is a slight unknown. The seatsides have a hole in the right side and not in the left side for the lapstrap to pass through. However I have read that it should be a hole in the left side and not the right side as that is where the seat's raise lever was and it could foul on it.
As for the Y harnass, it seems to consist of 2 sets, the one goes to the back bulkhead as per the link you gave, the other one looks like it went to the joint between the seatpan and backrest.
From what I see in the pic of the pilot in the plane, the 4 straps are joined through the locking pin very high up on the chest and this would (had the second Y harnass not been attatched to the seatpan) not kept the piolt down it the seat during negative G.
I think I got it now, thanx allot.
Theuns