You can have the ends removed, machined, pressed in and welded into longer tubing provided you find tubing with the correct ID and wall thickness. That's what I did for the front section of my custom driveshaft to interface the transmission.

__________________
Tony H
W111 280SE 3.5 Coupe
Manual transmission

Past cars:
Porsche 914 2.0
'64 Jaguar XKE Roadster
'57 Oval Window VW
'71 Toyota Hilux Pickup Truck-Dad bought new
'73 Toyota Celica GT