If OEM is NLA, then I suggest you rummage through the coolant hose bin at Supercheap.
Just look for something approximating the shape with the correct diameter.
If you are real lucky, one moulded hose might do both sides of the car.
Bear in mind all those cowl hoses do is dump water and dirt straight into that notorious debris trap at the rear bottom of the front guards.
I repositioned mine to dump at an angle forward of normal.
Haven't had a rust problem again especially since I fitted GRP front guards