Possible SpaceX Starship Mk 1 propellant tank layout by Michel Lamontagne

SpaceX's Starship Mk 1 prototype, being built at company's Boca Chica launch facility in South Texas, is seeing some rapid development in recent days (prior to Elon Musk's promised update on September 28). New hardware is being attached to the prototype and we can start some educated guesses of the final Starship Mk 1 design which will differ quite substantially from the Starship renders SpaceX provided as recently as in May.

Canadian design engineer Michel Lamontagne has posted his speculative graphics of the possible Starship Mk 1 propellant tank and fin layout on NASASpaceFlight.com forum (where he is known as lamontagne). More of his spaceship renderings here.

Images from the construction site indicate the header tanks (meant for propellant needed for landing) are installed into the front cone of Starship Mk 1:

But we don't know exact layout, they could be placed in parallel & possibly angled:

Possible layout of Starship Mk 1 fins:

Possible layout of Starship Mk 1 windward side heat shield with hexagonal ceramic tiles:

Graphic of Starship Mk 1 launch: