I received a reply from Hunter Pilant of Starline Brass today about the possibility of their producing 375 WIN brass.
In his reply, he stated that "we hope to be producing 375 WIN brass this year."
Might be worth the wait, rather than paying a fool's ransom for the 375 components on Gunbroker that I've seen recently.
Hope springs eternal.
PS: Perhaps more e-mails from interested customers may help build a fire under them to get the ball rolling.