I contacted Fred Medel at Tamiya America as I too broke a CVD pin (19440664/9440664) about 4 weeks ago. Here is his response...
7 digit spare part numbers are usually reserved for low priority wear items. 5 Digit spare part numbers are reserved for high volume replacement parts. Unfortunately, we didn't think this part through and have placed a large order for these pins to meet market demands. I'm sure this item number will switch over to a 5 digit replacement number soon.
Just wanted to keep you all posted. We should see CVD pins available soon.