
So, we need the following:
1) Compound recipe for say, 1925 vintage Victor / Columbia / Brunswick discs.
2) Recording lathe with correct stylus and pitch for 78 rpm non-micro groove.
3) Plant / jobber to press them.
In my developing vision for this, the source music would come from modern analog or digital masters, mixed to "mono" ( a "stereo" pressing would be pointless ), perhaps sending the source through a choice of a couple of EQ patterns, to approximate: pure acoustic "horn-recording", early Western Electric, early Columbia, what have you.
It would be worth experimenting with a modern "flat" EQ ( utilizing modern high-end mics), and sending that direct to the master.
None of this seems insurmountable, given the limited technology and manufacturing processes available to the folks who were doing this 80-100 years ago... ?