Billy Williams. Yaz. Hank Aaron. All played some 1B. Can’t say if they played it well.
Notable theme here seems to be that moving outfielders to 1B and accepting the costs of that seems to have stopped being a thing when the DH came around. I'm sure some guys can do it, but in general if a guy has the skills to play infield, teams use that skill the whole way up, even if only occasionally (see the A's with Mark Canha for a recent example).
Even being able to play 1B at a major league level as a backup skill is sufficiently valuable that you see guys in the upper minors regularly switching back and forth between 1B and corner OF mid-game, including guys who are likely destined to be outfielders in the majors (same thing you see between the corners and CF, by the way). It's usually apparent within a couple innings whether or not it's a feasible project. That's a large part of why you rarely see that switch attempted in MLB these days: teams already know whether their OFs can play 1B or not because they tried it in AA.
And on the rare occasions they don't, you get to see the experiment done on a major league level. For example, the Dodgers tried Joc Pederson at 1B a couple years back. They decided not to accept the costs of that.
