You have specified Model 700's but most of the SAUM chambered rifles were Model Sevens and those are usually fairly easily found on Gunbroker or Gunsamerica. I see them fairly often.
I have a couple Model Seven SAUMs but none are for sale.
The Model Seven Stainless models with the tupperware stock had a "magnum contour" on the barrels and these are great shooters if you can find a McMillan Alaskan Wilderness Rifle Stock to fit on it.