I have made several from sheet brass. .015 from the K&S display at the hardware store. Just lay out the pieces figuring the taper and diameters needed and solder it up after rolling the end pieces using a short piece of tube for the center. Might take a little trial and error using paper and trace it on to the sheet brass.

Here's one of then on the side of my N28, it was part of the Weyman exhauster that pressurized the fuel system.
Doc
Well it wont let me post a picture, shucks!