6300 ohm resistor

[dtvmcdonald]

You could get one of these
Mouser Part #
588-L25J3K5E
and one of these
Mouser Part #
588-D25K3K5E
And put them in series.

That is what I did for my CT-100 when I got rid of the gigantic
selenium rectifiers and used silicon and needed to adjust the series resistance. (However, I had them in the used parts box, used for years but still like new; they were and are superior parts.)