Bob what holds it together how about a take apart picture?:
Willis

Willis - the venturi is a press fit onto the elbow. With .0005 to .001 interference, the plastic will yield enough to allow a hand press.
A mild knurl and some JB weld for insurance.

Bob Z.

Bob what is Torlon. Is it part of the Delrin family?

While employed at Northrop-Grumman we were researching some various Torlon compounds, including 4301, a bearing grade variant.
The intent was to find viable alternatives to metallic bushings for aerospace applications.
The material was eminently suitable for the harsh conditions both in corrosive atmospheres (Phosphate Ester fluids) and harsh temperatures.
We evaluated both Torlon and Rulon, both showing excellent characteristics.
When I was a development engineer for Homelite, we used Rulon for wrist-pin buttons.

Since traceability is an issue in aerospace, we could not use the samples for production applications - hence, they went into the trash can and eventually into my stock supply.

Bob Z.