The bit that separated was the cylindrical bit (that is squared off at the other end and inserts into the motor shaft) from the square metal plate that has a hole in it that the cylindrical bit sits in and is tack welded together. That metal plate is still attached to the bars on the drum.
It's 5 years old and has roasted just under 200kg of coffee, plus a little bit of cacao and the occasional hazelnuts too. Not bad for the first repair needed.
New basket/drum has arrived already, great service as always Andy.
I'll still try and re-weld the shaft bit back on to the original once I borrow a welder, but no stress now if that fails.
Oddly, fastway delivered the parcel from a regular car instead of a van/truck. Must have had a small parcel round today.