help with crown tube for Oyster Patent + (Tudor and Oyster Watch Co)

[dgstr8]

I wonder if you can help with a question about crown tubes for the vintage Canadian (Oyster watch Co) cases and vintage Tudor oyster cases (eg 4540). The proper crown for these cases is an Oyster Patent + and the existing case tube appears to measure 4mm with a pitch of .4mm on the portion that screws into the crown and 3 mm with a pitch of .3mm where it screws into the case.

What I would like to know is whether this is a Rolex 24-6010 case tube. If it isn't does anyone know what it is and where I could source it?

Any help would be appreciated!