Bonanza, you are like my clone! I too am a lefty and owned that exact Ruger #1 Tropical .458 win mag for several years and actually used it to hunt an American buffalo (bison). I then sold it and later bought the Ruger #1 Tropical in stainless in the .458 Lott. I shot another bison with it and it did the job nicely. Then, one day, while I was at the local gun shop I came accross a Browning A-bolt in LH in .375 H&H. Yes, I bought it and later sold the Lott (I was just nervous that when I do hunt my African buff, that I may not be able to get the second round in quick enough). Both guns were really nice though, and I really enjoyed them.
The scope that I had on the Lott was the Leupold VX-3 1.5 - 5 x 20. An amazing scope, and it worked better than the Zeiss Conquest at about half the price too! I really don't know if I like my .375 too much. I took it out elk hunting a couple of years ago and then again last month and both times had a heck of a time getting my elk with it. Not too impressed. Good luck! Christopher