For the Pro's here

Does Marvin make their fiberglass window in custom sizes for retrofit purposes? Same question for you Pella guys, is their fiberglass line available is custom sizes for retrofit?
Now I;ll share something I saw today.....Andersen is making a double hung replacement window called the Woodwright. A true pocket style with a 3 1/4" jamb. The interesting part is I believe the exterior is Fibrex and the interior is available in four finishes. When I walked up to it I thought it was a Renewal.
What I find interesting is when they came out with the Renewal they really P O a lot of their distributors by not giving them access to it (other than the franchise route)and now that every lumber yard has access to what I'll call the Renewal 2nd generation how do you suppose the RBA people well handle it.
I do not hawk for Andersen, just sharing what I saw.

I'm not a pro, but I just ordered Marvin Infinity fiberglass windows to replace the windows in my house. They come in custom sizes, with three different exterior colors.

These are 100% fiberglass. They also make a fiberglass clad window (the Integrity) which is wood on the inside.

Yes and Yes.