You can buy new ammo for $20/box at ammunitiontogo.com
A couple boxes should supply you with a lifetime supply of cases unless you plan to make a shooting career with the .38 S&W.
You'll need proper reloading dies too.
The wrong-caliber-for-the-gun thing will get old.
You can likely find a box or two at the gun show.
Dealers usually have a little bit, and nobody is buying it.