The pressure data came from the Winchester pages on silhouette loads listed in Loadbooks .45 Colt edition. The figure is 30,000 CUP, not PSI.
I totally agree with your comments about not trying to turn the old colt cartridge into a magnum. While I have experimented with hot loads in the past, I gave up on them. I do have a couple of "warm" loads that push heavy bullets at about 1000 FPS, I rarely use them.
The question came up in the rifle forum under the "Home defense carbine" thread. Kieth Rogan, who lives in Alaska, is trying to determine if a Win. 94 Trapper loaded with hot loads and heavy bullets would make a handy wood bumming rifle for bear defense.