[35Z5]

I've not seen this type of resistor with tabs rather than leads and can't figure why it would be connected between heater pins on two ajacent tubes.
Any thoughts?
Larry

Raises hand..

If the 50L6 was once subbed by a 35L6, a resistor should be added to string, likely best location.. If resistor 30 has been removed or replaced by a lesser value than orig, a "make up" resistor could have been added between heaters of 50L6 & 35Z3...  

If tubes types match the schematic & R30 & 30A are correct value, it can be replaced by a wire & tossed into trash...