Interesting, as it looks like the centre pulley slots into the spur both sides... wonder if its all slotted together (using the centre bulkhead bearing spacing to hold everything together) , or screws are used... would be kinda cool to just be able to pull the layshaft out and change a spur without worrying about warping it by screwing it down too tight
I'm guessing the axle components are non set screw cross joints and holding sleeves.. not sure why a new axle is needed though, unless the sleeve is recessed into the outside maybe (knowing the TOP sleeves are tight in the hubs).
New diff halves, difficult to spot, but I know Elliott had been running ones with locking D rings this year... and thats the main change
On the chassis plate, one thing I've just noticed... the bulkheads are closer to together cross ways. The screw holes for the suspension blocks and bulkheads dont line up in a straight line like on the 416, with the bulkhead holes closer to the chassis centre line.. which is probably the reason for the new towers and upper bulkheads (look at satoshi's car, and the camber links are in the middle hole, at a guess thats the same position as the inner most hole on a 416) as well... pretty much no 416 bulkheads or towers are going to fit, so there's the new model designation reason!
Does look good though, lots of good small refinements...