Digi-Key lists Fairchild BU406FS-ND TO-220 pkg at 68 cents. Going with an original might be a safer bet.
Larry Pina says avoid ECG379, it can cause left side screen foldback issues in the raster.
ECG specs for the ECG379 read IDENTICAL to Motorola MJE13007.
I don't know for sure that your part numbers correspond to the MJE13007, but it seems likely.
Worthy of special note, comparing with the Motorola BU406 spec sheet:
DC typical betas over the sweet spot collector current range .1 to 1 amp are 50 for the original and only 20 for the MJE13007
Ft(min) is 10 MHz for the original and 4 MHz for the MJE13007
The switching times for the MJE may be ok but it may require more base drive than the circuit currently supplies to achieve them.
Although the typical Vce sat curves look fine, Vce sat max for MJE13007 is 2V, twice that of the BU406. Even when driven hard, it may not turn on as well as the original, perhaps the price paid to achieve the much higher safe operating area high voltage specs.
There is always a wide variation in beta unless the parts are selected. If you do some experiments, select some high and low beta examples from your lots to see if it matters.
Larry Pina says avoid ECG379, it can cause left side screen foldback issues in the raster.
ECG specs for the ECG379 read IDENTICAL to Motorola MJE13007.
I don't know for sure that your part numbers correspond to the MJE13007, but it seems likely.
Worthy of special note, comparing with the Motorola BU406 spec sheet:
DC typical betas over the sweet spot collector current range .1 to 1 amp are 50 for the original and only 20 for the MJE13007
Ft(min) is 10 MHz for the original and 4 MHz for the MJE13007
The switching times for the MJE may be ok but it may require more base drive than the circuit currently supplies to achieve them.
Although the typical Vce sat curves look fine, Vce sat max for MJE13007 is 2V, twice that of the BU406. Even when driven hard, it may not turn on as well as the original, perhaps the price paid to achieve the much higher safe operating area high voltage specs.
There is always a wide variation in beta unless the parts are selected. If you do some experiments, select some high and low beta examples from your lots to see if it matters.