Seemingly Unknown Shanks Brass Cistern?

Hello All,

I have a toilet that is very old and beginning to break down. I thought I could simply replace the antique brass innerds with a modern plastic version but discovered that the "down pipe" is of a much wider diameter than it's modern equivenants.

So I am trying to find replacement parts but am getting nowhere because I can't even identify the components.

Does anyone recognise this type of cistern?

The outer cistern is marked as a "Shanks 54/2", made in Scotland. The syphon is all brass and is also simply marked with "Shanks".

If I can figure out how to attach an image I will take a photo.

Thanks for any help.

Regards

bmak