Yes, you are right, there are also new Barrels in the old shape:

Weißfertiger Büchsenlauf, Original Mauser Argentino
ØD1 = 15,5mm
ØD2 = 16,5mm
ØD3 = 24,5mm
ØD4 = 28,2mm
G-Ø = 1.1" (12 Gang auf 1")
L = 740mm

is available from Lothar-Walther, but with 740 mm / 28 " it is not useable for a Stutzen stock I am afraid. And just cut it to 24 " would not be a solution.