I have done this exercise for my Lancaster curved top panel, this is based on a combination of tracing, drawing from a modelling book, photos and experience so is not definitive. Also I made this part by hand so I may have fiddled it slightly but from memory the dimensions were pretty good. I have converted your dimensions to metric in brackets.

BFP general dimensions – 14″ x 10-5/8″ with corners rounded to 1/2″ radius?
Mk IX Air speed indicator – hole 3-41/64″ diam. with holes spaced 2-1/16″ from centre?[92.5]. [52.4]Mine are 92.3-CORRECTION 92.8 and 52.4

Mk I Sperry Artificial horizon – hole 3-3/4″ diam. with holes spaced 2-1/4″ from centre?[95.25], [57.15]Mine are 96.8, 60.3

Mk I Turn and Slip indicator – hole 4-1/2″ diam. with holes spaced how? [114.3], [?]Mine are 111.1,60.3

Also, is there a general rule on how the holes should be aligned?
Mine are on a rectangular grid, reading across: 104.8, 115.9mm. Reading down 104.8mm

I measure the repro panel and it seems as if the top holes are all aligned on a datum 3″ from the top of the panel and the bottom at 3-1/2″ inches but with the Turn and Slip hole its too close to the climb and descend.[76.2], [88.9]

I have 74.4 & 89.5 so this sounds right. Yes the turn and slip hole is very close.

Just checked and my VSI fits flush to the rear of the panel on three screws with out needing an extra cutout. The ASI and the T&S are mounted on spacers to even out the front projection which would otherwise be excessive.

I remember something about the paperwork magically turning up in a dustbin in Port Stanley -is that right?

Tried to check this and found there were seven of these captured so no doubt the stories get confused.

1. I wonder if it could be a cleaning rod section for an AA gun?

2. looks like a stay for some kind of door or hatch

In both cases there must have been some reason to choose brass.

6a/1234 Type 104 Warwick A.S.R.I 496FG 🙂

Is it me, or is anyone else having problems searching for items on the ‘new’ e-bay search tool and getting the response ‘nothing matching your description’ even though you’ve picked one of their headings??

GYD

Yes it is working like it’s broken – giving no hits on a blank search. I expect they will unimprove it again shortly.

Hmm…
I can see where you are coming from but the 400mm is required to get the required reduction ratio.

Also, splines are one thing and gears are another.

Most significant though is that the reduction gear is a torque multiplier (power= rpm x torque in appropriate units).

This has been covered on this forum before and there is some good information about the chemistry (somewhere).

The quiet gauges are the odd ones out here, Radium dials are quite cheeky gamma emitters irrespective of condition.

This suggests to me that they were non-luminous or have been de-luminised exceptionally thoroughly. Try them with a UV light to see if they are fluorescent.