Re: how to make a cheap layback seatpost.
most seatposts are the same thickness as handlebars. i first started doing this in the late 70's with aluminum bmx bars. we were the only kids with cool anodized laid back seat posts.
the first production bmx laybacks were pretty much the same exact thing.
i've done this to just about all my bikes, and never bent or broke one.
granted, i'm only 135lbs, but as long as you don't extend it more than a couple inches, and don't jump stuff sitting down, it should work fine.
and yeah, BA, i cut up some vintage handlebars. there's more rust than chrome, and those "scout" bars are still available for cheap.