OK people, from a couple of comments it would seem there is some value in sharing the template I've used to make my Bastion, don't worry updates on that soon but before then I thought I'd share the template so folk can 'catch up' should they wish to do so. Here's sneak peak at where I'm at, hopefully help with understanding the plans.
And you'll need the larger of the double moonscape craters and it'll need to be cut something like this, I drew round the foamboard when it was constructed and used my Dremmel to cut the plastic.
So the template is at the link below, rest assured it's a bit whacky, well it does come from the mind of a Xenos. The difficult bits are the two cross members that are at an angle and NOT perpendicular to the centre line. Hopefully the top down views should give you a clue to how to cut the slots and the view of the crater has two yellow 8s the inner one is the roof and the outer one is roughly the footprint of the base and hopefully we'll taper all the way up to the inner 8.
Updates soon, but see if you can make hoof nor claw out of it ;)