The shirt looks to be an original Luftwaffe tropical in an un-issued condition and the Breeches look to be original Heer tropical examples, again in an un issued condition, though on these I am less knowledgeable.
If there is no 'history' to prove these were issued to the DAK, then they are tropical, still very good items, but not DAK. Any condition luftwaffe tropical shirt is very unlikely to ever have been issued to the DAK and certainly not an un-issued example, IMO.
The 38 on the shirt is the neck size in CM's.
Thanks for showing such good looking examples,
PS THIS IS IN THE WRONG FORUM!
Whatever its just an opinion.