Peter, I guess this is going to remain a bit of a mystery – many thanks for all your thoughts. I agree that there is little doubt that both the panels we have considered only have two fasteners visible from the exterior, but is it possible that they had a third on the interior, not visible from the outside of the aircraft and not appearing in the diagram? The panels would have had to have been secured at their base by some means, albeit that it is difficult to tell just what this would have been. If anyone else can add anything to these thoughts, I would be very grateful to hear.

Sorry to prolong the discussion over our panel piece, but I am trying to get my non-engineering brain into gear. I attach an extract from the diagram of the outboard engine showing the access panel with its two fasteners. Let us assume for the sake of discussion that this is our piece, although what follows might equally well apply to the one on the underside of the wing for the picketing shackle point in my post #515. The diagram is obviously shown in only one dimension and the two fastening points at the top in the diagram match ours. But this would not be sufficient to secure the panel in place, and there must have been something at the base (such as a flange?) to provide another (hinged?) anchor point. Is this not what we see in our piece?

Laurent has just e-mailed me point out that are two small rivets positioned between the two corner fasteners – these are just visible in the photos in post #513 – these may have secured an identification ‘label’ such as can be seen in a different position in the picture in post #515. Size is also relevant – our piece is about 22cm (or about 9 inches) wide. If the size is right, everything seems to point towards us having found the access panel on the outboard engine cowling. Could this be right?

Laurent is also satisfied that the supercharger clutch shaft bearing seems to have been correctly identified.

WV-903, according to the information I have it is from the supercharger gears.

Picture attached with acknowledgements to FM104 project. The right-hand picture needs to be rotated approximately 90 degrees to the right to see the comparison. I think the clutch shaft in the left picture is at the top of the right picture.

Peter, what about the inspection panel on the outboard engine? The diagram in AP 2062A (Section 5, Figure 3) shows a panel with two fasteners in the right position?

What is puzzling me is why (if this is an inspection panel) there is a third fastener, and why the sides are riveted with protrusions on the inner side – what is being attached to what?

Thanks for checking, Peter. It seems we may be in the right ball park – the shape is right, but nothing quite matches. Is the golden hue as a result of oil, I wonder? I suppose there may have been wartime variations to cope with damaged parts?