Here we go then. The second coming worked out fine. Printing on several kinds of metallic paper showed me which ones were and which ones weren't fit for printing at all.
So I started out with the first stage. Gotta start somewhere. This whole rocket actually is just a tube. Almost no hard conical parts apart from the boat tail and the fairing. Anyway, I tinkered some with the first stage and added the interstage section to it. This originally was designed to be at the second stage part. But while staging, the interstage stays on the first stage. So I changed that.
A curious thing with U.S. rockets is that the Titan has been the only rocket / missile that mimicked the style of staging the Soviets did. It meant igniting the second stage while still attached to the first stage. For this method they needed blast holes in the interstage and so this is a rocket that has a lot in common with actual Russian hardware even more so, because this is the only U.S. launch vehicle that uses hypergolic fuel like the Russian Proton, instead of the more common method of kerosene/oxygen or hydrogen/oxygen.
The blast holes in this rocket model were made from drywall mesh tape. I painted it black and used some extra CA to stick it to the insides of the interstage walls. Another layer of silvery paper was glued over it to conceal the overlay. The interstage actually needed some thorough reinforcing, since this paper is really thin. CA to the rescue and now it feels quite sturdy.