I wasn't content with the bright cabin lights and the front coupler on the new Lionel Doodlebug.
So, just a "small film" of orange paint on all 4 LEDs that light the cabin brought the brightness down nicely. You can remove the paint with rubbing alcohol and redo the effort if you're not pleased with the first results.
Second, I removed the front claw coupler and replaced it with a Kadee. The front truck is not the powered truck so one bolt removes it. As well, you will have to undo the wires for the pickup. The rear coupler is not as offensive looking due to the diaphragm covering a good portion of it.
I chose to drill and tap for the Kadee but you could just as easily glue it in. Lots of room to work once the front truck is off.
Tinkering on a winter day........................ Dave