On my 1st Gen Model T realized one of the 6550s was inoperative. Discovered I have an open resistor R40 at pin 4 ,which if open drops the 500v to the grid of the tube. Its a 1.5K, 5 watt white ceramic resistor. Wonder if anyone knows a source for this type of resistor,or have any spares in their junk box or parts drawer they would be willing to part with? Thanks..* Mark