Oh yeah. I am looking at that SoBo this year, so here is what I have. There are two ways into 60 Lakes along the lines of what you have described; the long way and the short way. For the long way, you bang a left at the Kearsarge/Charlotte junction and find your way to Gardiner Pass. The short way is to proceed over Glenn Pass from Kearsarge JCT and bang a left at the 60 Lakes junction at the base of Glenn just before crossing the isthmus between upper and lower Rae Lakes. Both routes meet up on mapped trail in 60 LB, and then (after a litlle XC, maybe) with a use trail that returns to the JMT in the area of Arrowhead Lake. The long route adds something like ten miles, bypassing about 6 miles of JMT including Glenn Pass (a main and worthy goal for me). The short route does not add much if anything and bypasses a couple of miles one of the most crowded and popular sections of trail, another main and worthy goal. I am having a lot of fun piecing together these routes from a number of sources, and I am not going to spoil your fun by simply giving them to you. But if you are good with the USGS 7.5' quads, Tom Harris and CalTopo, you'll do fine. That said, know that Lizzy Wenk did the long NoBo route last summer, with her kids, and that the "shared maps" function on CalTopo is cheating. I'll be glad to supplement this info as I refine it for my trip this summer. If you are interested in any other alt routes, let me know. I am mapping out Pine Creek Pass to Cottonwood with only about 38 miles on the JMT.
Wherever you go, there you are. SPOTMe!