John Boren may be able to answer that question.

In my view, the special plastic parts aren't that critical to cloning the model, at least not for sport flying purposes. The plastic nozzle set is an ornamental display piece, and is set aside for flying.

What makes the nose somewhat unique is the inset molded grooves that mark out the bottom one third of the nose, denoting the heat shield area. Well intended, but odd when one considers that those grooves aren't replicated on the airframe. They certainly were useful guides for masking around this area for painting, but one had to be careful about masking tape placement to avoid any paint bleed through on the underside of the tape. If I were to build another, I think I'd just use a regular old Big Bertha nose, and work out the masking area by hand. If one didn't know that the kit had a special variation of the Big Bertha nose, no one would be the wiser.

The parts that do require some consideration are the embossed cardstock corrugation sections. Replicating these does require some scratch building, and were I to build another, I would likely still scratch build these parts, as the cardstock versions are a bit subtle for my taste, and I found I had to do a fair amount of fitting/trimming of the wrap to proper seat the thing on my model. My partial kit didn't have these parts, so perhaps others can comment on fit, but I'd be worried whether the stock kit part would have enough slack to properly fit my build.

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John
YORF #003
SAM #004