BLZ is a small french manufacturer who made trains in O gauge from 1945-51. The American type loco, inspired by the GGI of the pennsy railroads is a very common piece in France, it has been a succesful model. BLZ is from the initials of the three associated people who ran the manufacturing in Paris, Bourdeaux, Lheurre and Zedda.
The most common one is the green model and after the brown, the very dark brown one, near black is the rarest. The power intended to run the trains is 20 v AC. In fact a Lionel ZW will work perfectly and those locos are very good pullers.
Here are three models,