Haven’t purchased any top or interior components from Macs but have purchased plenty of other parts. One thing I would suggest is calling for the true parts availability. Just because it says available online when you order doesn’t mean they actually have the part there and will ship within a day or two as you would think. After several backordered orders I realized they rope you in for the wait, seems to be a common practice with ecklers group (Macs is part of the “ecklers family” as the site puts it). Experienced that ordering el Camino and corvette parts thru ecklers as well.
Good luck with your top!