2 watt 1 ohm 1% resistors?
Mouser 71-CPF21R0000FKE14 62 cents
Mouser 71-RS02B1R000FE70 66 cents
Digikey WHC1R0FET-ND 88 cents.
SOme were Vishay, some were Ohmite, and if you can;t find 1% 2w, look at 3w, or 2%. Bias isn;t that critical anyway.
I know US suppliers shiiping to Germanywouldn;t be efficient, but if most of our large parts houses have them, isn't there a large parts house or two over there? RS maybe?
I see no problem with a single resistor, especially if you don;t have individually adjustable bias anyway. it all depends how much noodling you plan to do. If you want to know what each tube is doing, then spend the extra buck and mount individual resistors. If you are concerned that one tube may be way off from the other even though the total seems reasonable (like one really hot tube paired with one really cool tube) then mount two resistors. If you are not installing odd tubes, then use one. I generally install matched sets of tubes in amps. Very rare would I repair someones amp by sticking one new tube in with old ones in the power stage.
And the diode? SInce it is forward biased, and parallel to that 1 ohm, it wonl;t be doing anything until the voltage across the 1 ohm resistor gets over the juction voltage of the diode, roughly half a volt. Well half a volt is 500ma through the tubes, so they are in serious trouble if the diode has to come on. SO if I had to think about it, I'd say the diode is there to protect the resistor in case of tube failure. And note the resistor is a flame proof type, (Your metal film or wirewound types would be OK.) so they have that on their mind.