1" carbon steerer tubes were a rare item. I had a 2001 or 2002 (not sure) Giant TCR frameset with a 1" carbon steerer. The model year immediately after that switched to 1-1/8". I can't attest to what the third party sellers on Aliexpress are thinking, but we do know that many of them are resellers, and quality control is not necessarily a thing among the resellers or whatever factories they get their stuff from.
I believe that Wound Up Composites is the only firm in the West (excluding Japan, whose market is more opaque due to language barriers) making a 1" carbon steerer fork. On their site, they currently list a 1" compression plug made by FSA. Profile Design may or may not have a plug also compatible with a 1" carbon steerer.
If I were looking to replace a 1" threaded steel fork, I would either get the Wound Up fork, which may have a lead time as it's made to order, or I'd look for a 1" steel fork. Soma Fabrications appears to sell one model, for example. I realize the Wound Up article is possibly 3x the price of the Soma. This is where it becomes a personal choice. If the frame has that much sentimental value, then one perspective would be why not splurge. Another perspective is that a steel frame with a 1" steerer can only be modernized so far, and the marginal benefit of something like a Wound Up fork versus a well-made steel fork is not necessarily that large - I think I can speak from experience on this one, having a retro-modern-ish steel frame (albeit made in 2007) that has fairly modern components but it has a 1" steel fork (and stem).