basicly the same unit but with the inlets and outlets arranged to allow it to fit in the tight area I reckon, great work , here is another pic , Kev

Here it is on a Hecules II III or XI engine I think varialble pitch control
So question is what did the pitch control unit look like on the Tiger engine (Whitley) or the peregrine engine (Whirlwind)

numbers on body below adjustor All as far as can see DTD255 then an inspection stamp JSC over 53 in a tiny circle then A2K38
on larger part of body CA16708 K2366
Also found a reference to Stirling BK610 MK1 abandoned 1.5 miles East Dungeness , I take it that normaly means abandoned in the air? so possibly one candidate as if it is a Stirling part it would have to be a MK1 as Cable throttles were adopted for MK3 any help appreciated Kev

could it be to protect the edge of something as it was being rodded or something being threaded in?

entirely brass only markings are crown over AM and 1943, the grooves on the back that centre onto the hole look like they are there for a reason.
the bottom plate is not dead flat but slightly raised on each side
being a joiner it made me think along the lines of a specific woodwork related tool but I suppose by 1943 there were fewer wooden components.

Here is another fuel wheel compared to the first[ATTACH=CONFIG]235891[/ATTACH]

still had no luck with this one so putting up for another go, Kev

is the painted serial traceable S? 704 perhaps SI 704?