The changes come a bit further up the food chain. The catalogues in the archive normally say what the tubes are and if they are 3 tubes or full set, plus what the tubeset is. Latter 90s stuff is probably harder to work out as marin started to have in house tubes.....earlier stuff was tange in various guises.
Pine Mountain, Eldridge and Bear Valley SE were the same.
Similarly the Bear Valley and Palisades shared a frame.
Below that they had some Hi-Ten or plain gauge tubing, this mix tended to vary over the years.