i agree thats a ugly mess, heavy rear axle in there,looks like 3/4 or 1 ton.
you could do like henry said or another way woulds be to fab a mount and use a rear coil shock setup . the spring will not hold much but will locate the axle.
just a thought. one couls also use a std rear auto coil in a mount and have a seperate shock, you still would need the leaf.