Very nice warming oven. It's nice to hear that you care for your vintage home.
It really bothers me that we can get so paranoid over perceived dangers. Ten years ago I did a gut rehab of a building. Walls were moving around and the 1915 wiring was completely replaced. Unfortunately, the new wiring was frequently an issue. Connections would get loose, etc.
I now live in a 1930's home. The wiring has been updated when a room has been renovated. In my case, the kitchen. The bulk of the home is original. The electric load on the wiring is light. When I replace a switch or receptacle, I have used heat shrink tubing to stabilize the insulation. When I have had the chance to see the wiring in the wall, it's fine, it just doesn't like to be flexed. That shouldn't be a problem, since I am not reaching inside my walls to flex the wiring.
I watch a lot of HGTV home renovation shows. I love them, but what I never do understand is the shock of people finding old wiring or asbestos in their old homes. I mean get real. I guess it makes for good tv. My one piece of asbestos that I found was removed by me and disposed of, crisis averted!
Sorry to have drifted the thread. I just hate the see this vintage=unsafe mindset prevail. I am more afraid of my newer things blowing up on me.