There were .357 magnums made in the #1A, but they are rare and the OP would probably get tarred & feathered by Ruger collectors if he rechambered one of them to .35 Rem, plus I don't know if the twist would work for all .35 Rem bullets.
The .348 has never been made in the #1, so unless someone's custom turned up, it would require a rebarrel.
FWIW, (if no one takes offense
) the #1AB was made in .338 Federal, and of course the .35 Whelan was made in the #1A. These are easier solutions if you want a .35-ish #1.
After thinking about it, though, a .35 Rem in the 1A would seem a neat idea, good balance of power & weight in a compact, efficient rifle
