I guess I could use S3ditor to do that, I could try and see what happens. Confronting stock game sh4 and the 4 blade mod I noticed that the propellers blades had the same direction, while they were inverted in the popular propeller fix mod (later included in some other works)...hope it works.
Thanks skwasjer...from the Olympus...a true Deus Ex Machina...indeed.