Brad:
It is an eletric box headlight. When the D&RG went to electric lights, they reused the old box light casings. The railroad was slow in replacing these with Pyle headlights. The 454 was probably in storage at the time and got a new light when returned to service.
Volume 5 Number 3 of the Rio Grande Modeling & Historical Society's Prospector magazine had an article about the topic by Bob Richardson and Gordon Chappel. There are limited quantities still available at:
[
www.drgw.org]
Jerry Day
Longmont, CO