From TYCO’s 1965-66 catalog, the Mountain Master (T6506) set came in two versions. One featured purple power decorated for Atlantic Coast Line (#T6506A) and the other listed version came with Union Pacific (#T6506B) F-units. This set followed TYCO’s number practice of the time that employed the year of release, in this case 1965, as the leading two digits (65) in the set’s number and the the second pair of digits (06) appears to be a simply round of sets for that year. For 1965, you found 6501 – 6512 and then another group numbered 6520 – 6225. The latter group included a power pack, while the lower numbers came without power pack. The sets did include track in all cases, according to TYCO’s catalogs. Additionally, you find TYCO often included the retail price in the numbering on the package. For example, a label showing “T6506B2498” translates to the Union Pacific version of the Mountain Master and shows the $24.98 pricing in the stock number.
The Mountain Master featured a powered F9A and non-powered F9B with gondola, refrigerator car, operating hopper, skid flatcar with culvert pipes, and the streamline-cupola caboose. Though the set comes with an operating hopper car (#T330), there is no accessory for its use. TYCO sold Automatic Coal Unloading Trestle (#862) as a separate release in 1965 for $6.98 that would enable the owner to see the hopper in action. In the illustration, the operating rib-side two-bay hopper car is the blue Boston & Maine car between the yellow-orange refrigerator car and the red skid flatcar with three round gray culvert pipes. TYCO supplied brass section track that included 11 pieces of 18-inch radius curves, one curved terminal section, a regular 9-inch straight section, and a straight 9-inch section with re-railer.