I have a DHModified tenor (made for Conn by Keilwerth, similar to Superba).
I got an Oleg neck that suits it well.
Blows brighter and more focused than the original neck.
Apparently there are two tenor neck offerings by Oleg, one for Selmer tenors, and one for Keilwerth tenors.
Another option would be an aftermarket Keilwerth SX tenor neck.
They pop up occasionally in the forum's marketplace. Kessler's used to sell them new.
You may have to get a tech to fit the neck tenon to your specific tenor.