The VI you mention was (and is) part of traditional DAQ. By default, traditional DAQ is not installed with 8.5 but it does come with the rest of the drivers. It's on the Traditional DAQ>Counter>Intermediate Counter palette and you should also have been able to find it in your original porgam and determined the path. It's in vi.lib\DAQ\ctr.llb.
I agree though, that it's proably better to rewrite the program to use the Delay function but since the input to the Delay function is in seconds and the Wait+ has either millisecond or second inputs, it might not be just a simple replace.