Gauge 1 Aster Union Pacific Challenger 4-6-6-4

A gauge 1 Union Pacific 4-6-6-4 "Challenger", at just under four feet long one of the largest and most complex models offered by Aster.

Made in small quantities - with most engines pre-ordered - the design sold out shortly after launch. Used examples come up occasionally - new, mint in box examples such as this one are a good deal harder to find.

Unsteamed, in original manufacturer's packaging with all documentation and tools.