You can now see the resistors and capacitors from grid to ground used on the older AL-811H amplifiers. These often burned out if the tube arcs. Some of these were replaced by the seller with inductive resistors, explaining why the Parasitic Choke Resistors also burned out. You will need to remove those components and replace them with a ground lug that attaches to the mounting screw nearest the grid pin of the tube. Once you have installed the ground lugs properly in contact with the tube socket grid pin, solder the lug directly to the grid pin. W8JI arrows on his photo states: "Ground grids directly!" VERY IMPORTANT; DO NOT OVER TIGHTEN THE SCREW. THESE SOCKETS ARE CERAMIC AND MAY CRACK IF EXCESSIVE FORCE IS APPLIED. Also, this procedure is simpler than the one recommended by PA0RFI, which requires that you remove and rotate all tube sockets 180 degrees to get the grids pointing to the center, where he uses a wire to ground them at a central ground lug. This is a lot of work, and the sheet metal chassis is probably a better ground than a wire of any size.
Now that the grid resistors and capacitors are removed and replaced with a direct short to ground, we install the GAS TUBE, SURGE ARRESTER, 150V: #304-6015 (QTY: TWO) from each filament lead to ground. These normally do not conduct except in the case of an internal tube arc, which may occur in Chinese tubes. Connect them directly from a filament pin to ground, as shown in the W8JI photos as "Gas Arc Protect". You can see a close up of one of them, from the filament to the NEW grounding lug at the top of my photo. The second one is at the lower right, just out of view. Be sure you install one gas discharge arc suppressor on EACH filament lead, not two suppressors on ONE filament lead.