The crew of customer service/ support are at the HQ. So is one of the model shops.
OP send me a private message and I will get you names to ask. I dare not name names on a public forum...ya'll are animals
If they ran out...then ask for the supplier name by asking for help from supply chain management. Remind them that they are built in Corona, it will help them track it down. Also please bear in mind that they are "normal" people that don't know product like we do, its not there job to know a brand that they do 3 weeks of work out of a year for. I can tell you for a fact that its not an originally tooled knob. so many people have made them.
That being said a little more searching online and you will find the knobs.