Thanks to Stationx for posting the schematic.
I was hoping I could maybe use 2N458A in place of the 2N2147 however I'm still unsure whether or not I can use it regarding the HFE.
https://alltransistors.com/transisto...ransistor=4205
https://alltransistors.com/transisto...ransistor=1647
The power transistor line up that was in it was a pair of OC35 and a OC20 meaning that it already has been looked at...
The pics below show what I was greeted with when I removed them, one of them was missing its pins, that might explain why the current limiter doesn't work and its very unstable.
Regards
Poppydog