Astro Vent Rubber ducts?

[judge1111]

Pulled these out of my early build (09A) 68 RS and was looking for replacement ducts since the rubber is dry-rotting. However, all I can find is plastic replacements...
They seem to be original with factory staples top and bottom but cannot find any reference to rubber ducts...anyone seen these before? Thanks!

[Sauron327]

I've never seen those boot types on the 68's I've worked on or parted out.

[judge1111]

UPDATE: The 1968 AIM, sheet M1, shows the Duct assm. and parts were changed and STAPLES removed in Jan'68 but the connector was unchanged from plastic. Can't find any information on the prior duct assembly or parts...this remains a mystery.