anyone remember the RGR preamp from the early 80's

I owned one of these. Very poor construction quality by today's standards - used cheap strip RCA connectors. As I recall, the designer kept changing the tonal balance of the unit as noted by reviewers. It had detachable circuit boards inside. It had defeatable tone controls. It was relatively expensive in its day.

I owned a model 4, sounded great but had some reliability issues as I recall.

Yes, I owned the RGR Model 4 preamp and till this day regret selling it. It had an excellent Phono section and was truly way ahead of its time. I saw one listed on AA early this year at $175.