You are going to have to do some digging, or ask around. Or they may be lost to time, who knows. Here are couple more links, there are others but will leave the search to you.
PizMIDI plugins binaries for Mac and Windows - Plugins - Gig Performer Community
VST MIDI Delay? - Cantabile - Cantabile Community
Piz MIDI Utilities: Archived Download Links | Paul Cecchetti Music
WRT scriptlet, I was referring to the @dhj script that has a link to it in the post above. As he said, it one of the more trivial efforts in the grand scheme of things. At the end of they day, GP provides the tools to do this yourself, and add as many features or whatever you need for your use case.
And here is a paid VST that specifically says it does MIDI delays. But MIDI Lab is overkill if you only need note repeats with tweakable velocity and gate which you can do in GP with scripting.