10 ohm R's going high - problem.

[ppppenguin]

I find it hard to see how cathode resistors will suffer pulse overloads. If it was a long term overload you'd know about it.

If these Vishay film parts are really no longer trustworthy then it's time to look at wirewound. By their nature they will either be the correct value or open circuit.

To my surprise you can get 1% wirewounds for not too much money:
http://uk.farnell.com/vishay-dale/rs02b1...dp/1167848

Or the usual 5% parts such as: https://uk.rs-online.com/web/p/through-h...s/4851717/