HELP!

I hoped to purchase and take a new 2019 Diverge Carbon Comp on a long bike tour, anticipating a mix of tarmac, gravel, towpaths, etc., not camping, so "light" touring. But first I need to mount a rear rack (Tubus Logo Evo) and so far I have failed to source the currently-unobtanium Specialized seat post collar with rack mount in the 30.6mm OD, as seen in the flesh in the post 552 above by Winston63. (Thanks for that photo.) I understand the Specialized part no. is S 184700001.

My LBS says the Specialized parts dept. says 30+ days back order. I've called all the LBSs in town, and I've called several of the largest US Specialized dealers, they all have zero or negative (e.g. they are also backordered) stock.

UPDATE:
My LBS found they could provide a Spesh 30.6mm seatpost clamp w/ rack mount from an in-stock aluminum Diverge. Problem solved.