I don’t know. You’d have to ask Steele.
But remember that there is a big difference between a metal car and a fiberglass car in thickness of material where the rubber gasket is fitted to the body, so an original 356 window rubber probably won’t fit, I don’t know.
That is among the many reasons that building replica coupes means sourcing a lot of esoteric parts, like glass rubber and trim and those pesky little latches on the rear quarter windows. It takes time to find cost effective parts or get them tooled and built custom. “Stoddards” may not be the answer.