Guggenheim Partners Gulfstream G450 N385GP for the HTAI model.
These are textures only.
The HTAI Gulfstream G-IV model is required.
It can be found at http://htai-models.com/downloads.html
The converted P3Dv4 model can be found here:
Flightplans available here: https://aibizjetproject.wordpress.com/tag/guggenheim-partners/
EDIT 18 AUG 2022: Paint updated, new tailnumber