Steampunk Walker - bit more

Not been much in the way of development on the Steampunk Walker.
That's because i'm still looking around for the upper gun affair, made difficult by not knowing quite what i'm looking for.
I know: it'll be a sort of barrel affir, with a stubby gun barrel coming out of it, fixed so the whole thing has to turn to change where its firing at, a couple of chimneys to the rear, and a ladder hanging down at the vack.
But there's been a wee bitt of progress with the command ball that'll be slung underneath. I've backed the rear of it with Plasticard and started to add kitbits to pad it out. And i've attached an arm which coonects the ball to the body - the eagle-eyed will spot it as an engine from the old MPC X-Wing kit.