The database to which Evgeny refers is the
LEMB Sktz Database Homepage, an open resource listing Sktz, Wehrmacht Luft and civilian codes. With regards the Bf110 you list, there is a good chance that if this was used by a training unit, then it would have retained its Sktz code. Therefore, it may well be worth considering that it could have been ?T+ZH or T?+ZH with the ? being another letter...
Cheers
Peter D Evans
LEMB Administrator