I have not. I saw more than a few of the GN cars with conversions to hydroboost though most went to vacuum booster. It should not be too big of a deal if you get all the right donor parts. The early Cadillac diesels had them and so did the early GM diesel trucks that used the Olds engine if I'm not mistaken. A quick google search says they were in mid 90s Astro vans. I'd think the master cylinder would be the same and the power steering pump you already have should work. It does say that the little can on the side has a lot of pressure, like 3000PSI so don't break it open. It's worse than the spring in the sportwagon tailgate at hurting people.
