The photo posted is not the one with missing parts.
Maybe that will help the parts to re-appear.
it says mt5 but I tried the only mt5 thing I had and it didn't fit. I didn't spend much time on it though and put the chuck back on. It is strange that mine came with 3 jaw and a 4 jaw self centering chucks.
Just to clarify it is indeed MT5.
I bought one of these from Amazon "MT5 to MT4 Morse Taper Adapter Morse Taper Center Sleeve Reducing Drill Sleeve 5MT to 4MT for Lathe Milling"
then a bit of hard turning later and out popped a
made a drawbar and it works really well, very very rigid in this paper thin 38mm spindle tube.