a model locomotive found on Facebook marketplace, is one of 4 locomotives that were built by the Pennsylvania Railroad for use at the 1926 World's Fair in Philadelphia, and the only one ever found, the others have been lost to time.

This is in Train Collectors Quarterly.

https://www.facebook.com/madison.kirkman.18/posts/pfbid09jrDYQ98PJKqQE6spnYAdDPAnxdFeZVwsv8NuSFShRnw2E8tQS5Bcr8tb57vGw9jl