Thank you all for your replies!
Unfortunately the dial size must be from 26mm to 27mm. That is what the case accepts. Helenarou dials are too big, as are most I can find on eBay!
I have not checked etsy yet, I will have a look now.
The newolddials is a possibility, although having a real pocket watch dial would make it a bit "cooler " I think!
@AJ, a custom dial would be awesome, but I'm looking to keep the cost down for this one. I will PM you if I decide to do a fully custom watch.
There are a few dials that have the correct size, but my main concern is the sub-dial position. So my question is, is the distance of the seconds hand always the same? No mater the movement? If I get an old Elgin or Hamilton dial, will the holes overlap?
Thanks again for all the help guys!