I have found reference to the following items:

AV.250A Watch luminous
A.V.687 Watch and holder, Moth type

Does anyone have examples of these watches or know who made them?

Regarding the "holder", I am reminded of a WWII Air Ministry watch holder, made to attach watches of about 16 size to the instrument board. These were molded from black rubber with a king's crown A.M. However, I don't have an example to post.

In regard to the Watch and Watch Holders, I do not recognize either of those numbers, but I understand that all Tiger Moths were fitted with Watch Holders of some type.
Those TM’s made in the UK would most probably have had one of the RAF Watch Holders with an RAF part number, but in your part of the world Craig, could it be that the reference you have is to a Watch Holder from an Australian made Moth? I know lots of TM’s were made there during WWII, and I doubt if they would have used RAF part numbers in them. Could the A in AV stand for Australian by any chance?

I have a friend in Washington State in the US who knows someone who flies an Australian made TM, and I have asked him to contact the owner to ask about the Watch Holder if one is fitted. If anything comes of it I will let you know.
I expect you have the information contained in the attached, but it is extracted from an RAF parts manual of the era, and shows and describes the various Watch Holders listed as RAF parts.
At least it will let Greg see that he was on the ball as usual, as it lists the one he describes in his reply to you.
I have been hoping for some time to find one or more of the RAF Watch Holdders listed in the picture, as I would like to be able to display at least one of the watches in my collection mounted in one of them, but so far I not been able to obtain one anywhere. I would be very interested in any sources.

Ben
I do in fact have the reference document that the watch holder image comes from. It is an excellent publication, however it has not answered by question in this matter. I attach the image from a document tittled "The De Havilland DRAGON 1934 model, Spare parts price list."
This shows that the part number AV.250A or AV.250.A, with a price as well.

here is the reference to the Watch and holder, moth type, A.V.687. I have failed to write down all the details of where it came from, so I am not too sure not document it has come from. I do not think it is from the parts book that the other image came from.