Barmar, we have the same Monty as you, a 2007 3400. We also love the halftime oven. DW wouldn't be without it. If you can't find the manual (I'm sure someone has it) I could copy ours and send it to you. Also, you can order a replacement metal tray from Apollo. We're thinking of getting an extra one, so I don't have to wait for a second batch of cookies while waiting for the first one to cool!
One thing we discovered when using the convection part of the oven, BE CAREFUL with metal pans, etc. Even though it is on convection mode, there must still be some static or magnetic buildup, as we discovered that when the turntable is turning, if anything metal comes too close to the edge of the oven walls, it WILL spark across. Need at least 1/2 inch clearance. So, just a word of warning on that.
I've done a few "mods" to ours, so if you have any questions, just ask!