The .41 AE case was very expensive to make, since they ended up with so much scrap after cutting the rebated rim. Quality Cartridge said they would only make the brass to fill orders, since at the time cartridge brass was costing them $6.24 a pound, and they were getting $1.75 a pound for scrap brass.
At one time, I had 2,000 rounds of virgin primed .41 AE brass, and 1,000 rounds of factory .41 AE ammunition. I sold it all to buy a Witness Elite Match in .38 Super, and still had enough money left over to buy some extra magazines.
If you locate any .41 AE brass, you can use .40 S&W loading data for it, with the same weight bullets. In fact, some loading manuals just refer you to the .40 S&W data for the .41 AE.
Hope this helps.
Fred