Good spot ! I hadn't made an issue of it as it's an area where Mark and I are "agreeing to differ", and it's only really an issue for the perfectionist. Let me explain .....
Here's a picture I found of a Tank Workshop (Fosters, I think) building Mk. IV's:
This clearly shows the mud chute deflectors angled differently to the build instructions. This makes sense to me, as there are pictures of the Chinese Labour Corps cleaning out mud with pressure hoses and, this way, they would be able to jet up along the top of the track run and flush the mud out.
Mark agrees that the pictures show it this way, as do the original drawings (which shows the impressive depth of his research). However, he assumed it was an error as, if you fit the plates as per the instructions, it enables you to clean the drive sprockets (which, apparently, works on his prototype build).
Historically, we need to bear in mind that the British Army in WW1 regarded tanks as throw-away technology - if they lasted 50 miles that was good enough. Therefore, cleaning and repairing them was not a high priority. The Mk. V was coming on stream, and it's clear from the historical records (one of which I've posted elsewhere) that the surviving Mk. IV's were getting very tired by March 1918. It is, incidentally, very surprising, and impressive, that the Germans did such a good job of cannibalising and rebuilding the few that they did !
And, to finally increase the confusion level, I think (like Ian) that I've seen other Tank Workshop pictures showing the chute deflectors the other way round (ie. like Mark's instructions) but, on inspection, they've been Mk. V's.
So where are we ? Firstly, it's a simple amendment - just drilling a couple of holes, and filling the old ones (I'll be glueing a rivet in). I did think of swapping the plates over (as Ian originally thought) but that doesn't work as the pre-drilled boltholes are a different pattern.
Secondly, it's a bit nerdy, as these plates are almost invisible once the frames are fitted together and the tracks wrapped around. So anyone who has irrecovably gone past that stage shouldn't panic unless they have the same type of anorak as I do !
Thirdly, anyone seriously intending to drive their Mk. IV through heavy mud (certainly not me, athough my wife is promising to build me a 'Tank Proving Ground' at the bottom of our garden
) would probably take the tracks off completely and do a detailed cleanup - far more than was ever intended in 1917/18.But, as I've said before, I think it's great that we can debate such minutiae almost 100 years after the event. Long may we do so, in a constructive and reasonable manner.
All the best,
Chris
. I was a bit confused by the tags (EK0635), which I couldn't find in the plans - it's obvious where they go, but inside or outside ? A photo of the box on the Aberdeen Proving Ground Mk. IV shows them outside, so that's where they are.
), and fitting the motors and electrical boards. Apart from that, it really does look like minor stuff (he said brashly, forgetting about that rear armour that has to be made). And, as I've found someone in the village who's a demon with an airbrush, I'll get help with doing the bizarre colour scheme I've chosen. So showing off my pride and joy, and meeting you all at Armortek Day in October, is now a real prospect !
) and then, with heart in mouth, pressed all the 'go' switches. And it works ! Liesel has a beating heart ! OK, it's only an enhanced bench test, but it's a hell of a milestone to me ........
BTDTGTDent 
