Hi Larry. If I remember well I believe you built a postwar type layout with the K line track and Lionel 022's. I have done the same thing in my former layout.
I used three foot wide bases(mine:semi hollow doors with homosote on top) with good success. The curves were all 031 k line tubular and lionel 022's .
I missed it so much when sold, I decided to build something like your apartment plan using K line second time around. Great for the space.
May I ask you what and how many curves (other than 031 too?) and straight pieces you (standard length or other ?) you used in your new plan? It's surely a neat plan with reversible direction possible. I can see your plan but not sure of all the components. Thanks for any help and cool ideas. I think I can build one like this. Have the doors and a few turnouts and some super snap.
Good luck with your plan.
Leroof