Just look on their website. Already there.
In the time it took for you to post that "helpful" info, you could have simply told me. Before I posted my question, already had gone to their website and didn't see date/version info which is why I asked. I'll look later when I have more time.
Road Number Specific ScaleTrains
UP 3612 and 3645
Phase IId2 units built in 1979 (UP 3609-3658)
Early electrical cabinet “zig-zag” seam
Standard exhaust
Extended-range dynamic brake housing
See through standard 48” radiator fan housings with fan blades visible inside
UP 3739 and 3754
Phase IIIb1 units built in 1980 (UP 3659-3768)
Late electrical cabinet weld seam on long hood and roof
Late electrical cabinet “”zig-zag” seam
Extended-range "Post '80" dynamic brake housing with exhaust silencer
48" radiator "Q" Fans
Mid-1980s era repaints
Gray trucks
24” nose medallion
20” cab numbers
Painted-over class lights
Small UP medallion on sub-base doors
Operating warning strobe light on cab roof*
88" low short hood with wheel handbrake
Class lights disabled and lenses painted over per prototype
Late sub-base doors with lift-off hinges
Bolted battery doors with large louvers
Cab with welded side window panels and standard sunshades
Motorola ASP-16 “Firecracker” antenna on cab roof
Retrofitted small “ice skate” antenna next to horn (EOT)
Leslie RS-3L-R Horn
Stand-off ECAFB (early)
Intermediate inertial intake grills
Corrugated radiator intake grills
Frame-mounted bell
Flush-style EFCO
Highly detailed 4,000 gallon fuel tank with fuel fillers and gauges
3-hose MU hose clusters
Forward engineer’s side sidesill notch
Straight uncoupling levers with “loop” handles
Notched pilot faces with lifting slots
Forward engineer’s side sidesill notch
"Tall" stepwells
Intermediate jacking pads
Late center axle snubbers
Detailed HT-C trucks with brake plumbing, traction motor, and air ducts
DCC & sound equipped locomotives also feature
ESU V4.0 “Full Throttle” decoder
Dual cube-type speakers
ESU designed PowerPack with two super capacitors
Operates on both DC and DCC layouts
DCC & sound ready (DC) locomotives also feature
DCC ready with 21-pin connector
Rivet Counter SD40-2 Locomotive Features
All-new model
Fully assembled
Four (4) different road numbers
Dimensionally accurate truck centers
Underbody frame rail with separate plumbing and traction motor cables
Sectioned treadplate detail on the walkways
Accurate hood door and long hood detail
Accurately profiled dynamic brake housings
See-through dynamic brake intakes with resistor grid detail
Factory-applied wire grab irons, wire lift rings, windshield wipers, snowplows, horns, coupler cut levers, and trainline hoses
Semi-scale coupler buffer equipped with ScaleTrains.com durable metal semi-scale E Type knuckle couplers
Directional LED headlights
LED lighted number boards
All-wheel drive
All-wheel electrical pick-up
Dual flywheel
Motor with 5-pole skew wound armature.
Printing and lettering legible even under magnification
Color matched to Tru-Color Paint colors whenever possible
Operates on Code 70, 83 and 100 rail
Packaging safely stores model
Minimum radius: 18”
Recommended radius: 22”