Acorn Pivot Shoe
What replacement shoe do you recommend, and what is the part # for the jamb/track spreaders? Thank you.
At first glance, your pivot shoe resembles an older version of our 15-015. This was also used by Acorn windows like yours. The only snag is that our dimensions are a little different; specifically, the 15-015 is 17/32" deep. I would remove yours from the window to confirm.
I actually don't recommend jamb spreaders in your case. Because this is a thermal break window, and because it's a little old, there is a chance you will crack the vinyl when spreading the track. I would check the top of the track to confirm there's not a cut out. If not, you can make one. See the video below.
I think the 15-015 will still be good. There actually aren't any other options, now that you mention it, so I feel confident recommending it. Like you said, that difference is minimal. Let me know if you need anything else!