Thanks for that
I was not sure it would be easy, but I have some ideas. I might be able to get a case of a slightly larger, or smaller size and have it adjusted in a machine shop to fit, or create some spacers to make it fit well in a standard housing. Even knocking up a custom housing from scratch is possible really.
I like the idea of doing something a little more difficult for a first watch, as it should seem a lot easier if make a second, more standard watch. This is not even an automatic, so it would be unlikely to be worn every-day, perhaps just as a dress watch. It would feel really special knowing i had "created" it myself