[Marsupial]

I am not certain what was the specs back then, but nowaday they are 5% AFAIK

910 instead of 900 is a bit more than 1% off, still well within tolerance. Just for fun, measure your 910 to see if it is truly a 910, or perhaps maybe a but lower.

rules of thumb, you'll want a bit higher rather than a bit lower, when replacing with a non-exact value.

Again, I don't know how it was back then, but nowaday, when the resistor value is critical, they have a trimpot that is adjusted at the assembly line, and shut glued in place to keep value there.

Those of us fooling with a defect radio or TV being young, adjusting those adjustment screws what had some colored goo on it, was doing a very bad thing. lol.

IMHO, the 910 instead of 900 should do just great.