So I had a bit of time and I put the Stormblade together. It's a nice kit which is not too hard to put together.
In fact the most pain in the butt thing is the way the floating wheel at the back wobbles about when you're assembling any Arkurian Baneblade chassis.
And the Macharius. The port side is a Macharius part, with the sponson in the correct place.
Someone somewhere has a Crassus with a Macharius starboard side piece. It's a genuine part, but the panels on the Crassus part are not as pronounced as those on the Macharius and are in different places.
Which is what this pict shows. The previous owner (careful, FSH, one lady owner) had smoothed off a little of the detail to fit the sponson to the vehicle. But this position is way too far back towards the rear. That sponson has to move forward.
It wouldn't sit without a little more flattening out of the detail. a couple of minutes with the dremel and we're good to go. Am I worried about the apparent level of carnage done to this expensive and detailed FW model ? Nope, I'm gonna glue a sponson over it and the paint and weathering are going to hide any overspill.