Good Morning from a sunny Brunei,
John Hawes got in touch last night and pointed out that my Speed Brake Stem (Items 17 & 18) were different from his downloaded version and that shown in my build video. During the video of the build I realised that if I designed the speed brake differently, the assembly would be much easier. I had forgotten all about the change until John pointed it out. Please find the zip file attached here, if you would like the modification for ease of build.
I have updated the base files to reflect this change from this point on.
Kind Regards Karl