After a lot of tedious work, I've been able to cobble together the texture files for the fuselage and tail using Blender and Photoshop. I had to save the texture files out one at a time after painting just the section of the airframe for each file, saving them with names which linked them to the filenames in the 2D paint kit. Slow, annoying, but in the end, the results should be OK. When I have reinstalled MSFS2024 and purchased the aircraft I will know for sure, but to date its looking as if it will all work. But until someone is able to convert the Substance Painter fbx to a Blender-friendly version this might be the only way to create a livery.