Replacement extruder for box +

Can I confirm which are the part nos for the
Abs, PLA, TPU extruders for the Box+?
e.g. is the BC0636 V4 - compatible with the box+, (being sold for box)
Are the items interchangable with the extruders in the U300?

Regards

I have been investigating further and i am slightly confused

I have found
BC1012 being advertised for ABS, sometimes for Box & Box+, sometimes Box+ only, sometimes Box+ & U300

BC1012 PLA ?
BC1017 TPU ?

Is the BC0636 V4 for the Box only or is it for the Box+ (or possibly U300)?

Is this the correct place to ask about these things?
Or am I missing a site with a list of spares (Annotated exploded view of the machines?) and associated part numbers?

Very many thanks for any help