Bulb Seal Weather Strip - Milgard

I am replacing old, worn wkindow weather strip. I found the Milgard Windows manual which shows the exact seal I currently have, but I am unable to find a vendor.

I would like to price the exact same weather strip I currently have:
Milgard Windows Vent Bulb Weather strip WS1354BUWH (see 3 photos)
The part that goes into the window is about 1/4 inch, as shown in photo.

Or, what would be a good alternative to replace this white weather strip?

I am looking for the same replacement weather stripping for Millard windows. Did the the replacement material work as a substitute?

This weatherstrip, 58-055, worked for my Milgard Ultra crank casement window. Replacing the same weatherstrip as QL,Hi. However, it's a little difficult cranking the window tight, because the new bulb, closes to the pivot point contacts first and offers a lot of resistance. The locking latch is also a little difficult to flip, but works.
I think it will abate in time as it gets squished more flat from usage.
Going to try using gentle heat on the first contact side, in the locked position, to see if that will soften the bulb enough to hasten the process.