The Metaframes have that sequence but not all tanks. The father of a friend had a Jewel slate bottom tank. There were four (or more) holes drilled in the slate. Posts were installed on top of the slate with the holes at the base. Then the glass panels were placed between the posts. The angle iron tanks that used to be around here were made all different ways. The last one I had I put in an auction a few months ago. The sides protruded down to form legs below the frame. It still held water with the original mastic. It was light gray, not the Pecora brand.
The silicone is flexible but I don't think you would need the support unless the glass is really thin, or a really large tank. If you used a filler, like JB Weld, you would have to sand it flat and still use silicone for the seal.
--- In firstname.lastname@example.org, "'Dick Houston'" <dickhous@...> wrote:
> Thanks for the input. As I am sure you both know the sequence of assembly of
> those tanks was front and back glasses first, then the end glasses