I'm not the expert on this but the media for three d printers is a risen. The computer takes the input and the printer has a roll of thread and melts it into the product. As I understand it there are a couple ways the process can be done.
Little progress . Got the seat belts in and fuselage halves partially together. Not fully glued, some fit issues but for a kit this old, not a biggie. Lower wing attached at the back. Need to leave it dry before forcing the front into place.
Dealing with some fit issues. Oh and how!
The forward fuselage aft of the engine won't come together. I made sure that the engine would mount and the cowling would be OK and I used plastic dowl to fill the gap, top and bottom. The aft wing to fuselage mate had a major step in it so I used card stock to work it out. And then the forward edge of the wing behind the bomb doors has a gap. Again plastic dowl.
For a kit first release in 1974, well issues can arise I've attempted three (this is the third) of these. the first, well I still have parts but that was in 1992/3 time frame. it was a disaster in fit and it had fits. The second was a peach, I don't recall any issues. So I'm not really surprised at this. I've posited a couple pictures earlier in this tread.
I built this model back in the late 70's and still have it on the display shelves. Didn't really have any fit issues with it but then the molds were still young.