I just found out that the Valenta Durban 4XL leather pouch is a great fit for the DM15L I guess it will fit the DM42 as well.
The sleeve that is delivered with the DM15L is nice, but this pouch has a luxury feel. It's only slightly thicker and wider than the original sleeve.
https://www.valenta.com/_127_w_3626_104873_GB_1
(I am not affiliated with Valenta in any way)
Luxury leather pouch for the DM15L
Luxury leather pouch for the DM15L
DM42 s/n 06181 DM41X s/n \(\beta\)0005 (sold)