The deadline’s approaching to do the right thing. Four o’clock today is the limit of the amnesty investigators are offering for people who came upon the accident that sent cash from an armored truck scattering across Interstate 80 near Grinnell this week. Officials who held a news conference earlier this week to announce they expect the money to be returned and added they’d arrested a couple from Las Vegas who picked up some of the cash and took off with it. By that time only 60-thousand dollars of the 320-thousand had been recovered. They’re asking clerks and cashiers to watch for the 20-dollar bills with serial numbers beginning with 2369001 and giving the serial numbers to banks and businesses so any of the money that’s spent can be more quickly tracked.