RAF Tropical Tunic question

I just bought this tunic which was in great shape and appeared to be authentic.
Hopefully I wasnt ripped off.
I am posting a few pictures and was wondering if anyone can tell me if it is an authentic
WW2 Tropical tunic.
I believe that the ribbon on the tunic is Africa Star?
Was this tunic worn with a T-shirt or anything underneath?
I was also wondering where I might find a matching belt and trousers.