I ended up buying an Ender 3 Pro (pro really means mkll in their case).
Worked pretty much straight out of the box ? printed a few test pieces in PLA and starting to get the hang of ABS . Very happy with the machine. Couldn't get the supplied slicer software to work but have downloaded Cura and that works like a charm
When making parts for the inside of the aircraft be aware that PLA (made from corn starch) will soften an temperatures that are common in summer. ABS is the plastic often used in motor vehicles, use it by preference. I used PLA for some support pieces for a bird restricted system, a week later had to make the 50 odd pieces out of ABS
This part was 3d printed. A test piece. Each end was bent to 12 mm deformation. It maintained its integrity. More interesting it returned to near its original Shope over the next few minutes. It is very tough, it didn't delaminate. This is so encouraging for the future of 3d printed parts. It weighs 13grams. Is 65x25x12. Carbon infused nylon.