Re: Lay back seatpost - with or without support?
On some of the old cruisers the seat post is an L shape and is solid steel. On my current Worksman NB build I used a 1942 Elgin seat and reversed the L so that in effect it is a layback post in that configuration. The diameter of the post is smaller than modern ones, so some shimming is required to make it work, which I did with a section of handlebar slit lengthwise in two, plus a section of copper water pipe also slit lengthwise. If you're after a vintage look it is one way to go.
Someday when I grow up I will probably lose interest in toys with wheels, but until then...