Reply to "First Lionel Diesel Locomotive in 20 Years and parts were detached new out of the box. Need a recommendation for a good glue."

I've replaced parts many times by using 5 minute epoxy.  I use it on even the smallest parts, but you need a steady hand to hold the small items still for 5 minutes.  It makes a permanent repair, so if you don't want to go through the trouble of sending it back or working with claims, give the epoxy a try.  I get mine from Harbor Freight in small tubes that are easy to work with.