I'm always the only one saying this, but I think continuing in RT 1971 would have been impossible because of all the contradictions between what happened in 1840 and 1966-70.     History was changed so much that the events and people we knew would have been retroactively cancelled out.

This may have been discussed mentioned elsewhere, but was there ever any rationale given for just ending the show the way they did in 1840PT instead of "going back home to mama" as it were.

I believe it was fairly abrupt. ABC cancelled the series and put a dame show in its place (Password, I think) since it was cheaper to produce and the ratings on DS were going down for some time. I suspect Dan Curtis and company didn't have too much time to wrap things up, although a final episode in 1971 probably could have been accomplished.

Indeed, was there any precedent at all even to bring soaps going off the air to any kind of conclusion or did they just end?

I agree-I think ending on a contemporary note would have been much better. Though I did like the tack on narrative where Sam Hall told how he imagined the future for each of the characters. Was that part of the original series, or something added to the dvd as a bonus feature?

[I always had the impression that Vicki had simply gone through the same motions that Phyllis had.  In other words, Phyllis arrived at the  Collin's estate addled from the carriage wreck, was accepted into the family as governess and became the scapegoat of Angelieque. In gaol, law student Peter Bradford took pity on poor Miss Wicke and after the trial went badly, he helped her to escape where she then saved Daniel, was recaptured and then hanged.  Since he had taken the rap for Noah's death, he too was tried and hanged.

I think the general idea is that history is alleged to be pretty solid (none of your "treading on a butterfly in the past will destroy the future").  Broadly speaking, as long as the major events take place, the smaller details of how they happened don't matter so much.  The biggest difference probably was that Peter fell in love with Vicki, where he had not with Phyllis, believed that Vicki was from the future and that belief allowed him to find his way to here in the present (this all could have been Sarah's spirit at work).  They found each other in the present and eventually (imo with Sarah's help) both vanished into the past that Peter was a part of and that Vicki had been so entranced by.

I believe that Vicky should be thinking - but I know it wouldn't do any good, because motive is no longer going to get her anywhere.  It is true that Angelique apparently got $20,000 out of her short-lived marriage to Barnabas - and in 1795 that must have been a fortune - but if money was what Angelique wanted, it would have been far simpler for her to marry Jeremiah.  If she loved Barnabas, then why did Barnabas die?  If she wanted revenge, then what did she have against the Collins family?  All three Dupres family members are still alive, and since she was a Dupres servant, surely it would be against the Dupres family that she would want revenge.  None of it makes any sense to a logical mind - but Vicky should still be trying to make sense of it.  It's her only hope.