Republicans make up much more than 34% of the electorate in Alaska, so it seems clear that some republicans voted murkowski, as well as some independents.
Actually Pubs make up just about 26% of the electorate in Alaska - 128K(R), 75K(D) out of 493K registered). The majority, about 55%, are either undeclared or non-partisan.
Miller got about 56K in the primary in a close contest, slightly more than Lisa (not writing her last name). In the general, Miller got almost 70K, while "write-in" got about 83K. Clearly I doubt Miller lost many of those 56K and likely gained a few of Lisa's voters who were sticking with the party above Lisa. From there we can see a little of how the numbers broke.