I am very much in the same position as you, rode some in the '70s, in fact much smaller bikes than the ones you mentioned, and I also consider myself a noob.
The 650 is definitely not too much bike for you, but it may not be the
right bike for you. In general the cuisers are not the bikes everyone is warning new riders about, at least until you get over 800cc. I think the VStar is around 35hp.
The two bikes you mentioned as having ridden are both standards, the v650 has forward controls, the best advice I can give you as go sit on different bikes and see how they feel, and ask yourself what kind of riding you want to do.
Personally I like the look of the cuisers but don't like the forward controls, they just feel odd and it is harder to shift position or stand on the pegs to give yourself a change in seating position or for a control manouver. But you will get use to them and you will probably like them. On the very wide bikes with forward controls I just feel like I am having a GY exam on them and I'm a man
Also I took the MSF course (well the canadian equivalent) and it was an excellent way to get back. I recommend the MSF highly (you will be bored to tears on the first morning on the bikes, but once the engines are fired up it's all good).
Good luck and welcome.