K5MO, that's a great resource.
It links to this:
https://www.yasme.org/award-call-signs/. . .which appears to be any call sign (some common, some rare) that were
ever linked to YASME in any way (past and present).
I did note VP8SSI in there (a fairly recent operation). That one was a big time operation to a difficult, dangerous place. Lots more stuff that was no doubt quite rare in the day, but also I did not see a lot of Bouvet or Peter I type operations. Call signs, farther back, did often have different prefixes than they do today, so I might have overlooked something. And, I didn't exhaustively read it. Maybe someone else can point out others. It would not be a lot and the dates would matter for this discussion also.
But, the call list kind of matches the stories I have been told over the years of those bygone days.
DXing just wasn't as big way back then as it is now. DXpeditions were simple affairs, not expensive, and didn't really have more than a handful of ops. The big 8 to 20 team activation does not appear to be what most of the activations on that list were. In fact, the majority was done by a handful of operators, including OH2BH, but also the Colvins.
A lot of warm water South Pacific stuff, so it's safe to say that "safety" wasn't a big discussion other than the ordinary hazards of operating a sailboat.
As we expanded the DXCC list, and expanded the list of the possible, things got more dangerous than they did in those early days. DXing, way back then, simply didn't have the budget it does now and just couldn't really go to such places I imagine. I have no idea when Northern Cal DX got big, but until it did, there was no way for a DXpeditioner to raise large sums of money or even apply to it from the foundations, which took a while to get to where they are today.
It all grew organically as far as I was ever told and the call sign list, and the dates, reinforce all those old stories I was told.
There was a day, whole decades probably, where "danger" as we have been discussing it, just wasn't a factor yet.
It has been a factor since at least the 1990s and following, though.