I think I'm done playing around with a plan. I followed your design basically with the trestle section, a little closer. Decided not to have most of the lower loop hidden and will probably follow your lead with a trestle at the lower outside. I also realized I can get by with a 30” turntable rather than a 34” saving a little space. For the most part the plan is a guide for benchwork and I'll certainly adjust as I go along. All I need is the nerve to tear down my existing layout! Since I’m really in no hurry, I may build a study model before I proceed with demolition.
Thanks again for the renewed inspiration!