In 1974, LEGO released 5 Trains 4.5V / 12V sets, all of these sets have been retired.
Most valuable 1974 LEGO Trains 4.5V / 12V set
723-2 Diesel Locomotive with DB Sticker $1,500.03
Largest 1974 LEGO Trains 4.5V / 12V set
725-2 Freight Train Set 425 pieces
Theme / Subtheme Trains / 4.5V / 12V
Year 1974
Pieces 98
Availability Retired
723-2 LEGO Trains Diesel Locomotive with DB Sticker
Retail $8.50
Value $1,500.03
Growth  +17547.4%
Annual growth 10.9%
Theme / Subtheme Trains / 4.5V / 12V
Year 1974
Pieces 425
Availability Retired
725-2 LEGO Freight Train Set
Retail $25.50
Value $1,353.68
Growth  +5208.5%
Annual growth 8.3%
Theme / Subtheme Trains / 4.5V / 12V
Year 1974
Pieces 1
Availability Retired
741 LEGO Trains 12 V Transformer
Value $96.68
Theme / Subtheme Trains / 4.5V / 12V
Year 1974
Pieces 12
Availability Retired
755 LEGO Trains Left and Right Points
Value $28.04
Theme / Subtheme Trains / 4.5V / 12V
Year 1974
Pieces 5
Availability Retired
756 LEGO Trains Electric Crossing
Value $58.19