[codefox1]

Tell the truth, just about any output transformer from a single ended tube set you can scrounge up will work. You can try to get one to match the likely 8 k load to voice coil (likely 8 ohms with the humbucker) by using a universal 3 watt replacement. Try to find the fault with the old one (nothing to lose by trying,) it might just be a corroded connection between t he winding and the lead(s.) Also be sure that nothing fried the transformer like a short or fault in the voltage divider network.