On 8MA1010, the sheath (8mm OD) is only ~30 inches long....it looks like the original setup by not positive!! So for most of its length, the steel throttle cable tube (~10mm ID) welded along the chassis spine carries only bare cable, no sheathing. The short length of sheath pushes into the rear of this tube from the engine bay, and only guides the cable from there to it's termination near the carb.
But....If you have a cable assembly with a longer sheath, it should just slide deeper into the tube to compensate. That said, I think a Pantera cable shealth may be bit longer than Mangusta geometry can accommodate, so some trimming MAY be needed. Fwiw the aftermarket Panteras cable's I've seen have OD's closer to 6mm than the Mangusta's 8mm, but that doesn't seem to be a show stopper.... End-to-end my throttle cable assy measures 76” (per notes!), terminations included.