Sometimes the cut leads from the tone capacitors are used depending on how long they are. When I want to use something solid for ground like that I've used paper clips, believe it or not. Works perfectly.
Btw, what's an "LPV Russian"???
Or even get solid core wire and just strip the insulation off
I guess you could use paperclips... I wouldn't because they seem very random in terms of material. Might not stick well with tin, or have high resistance. Grounding issues are quite usual "ghost in the machine" problems.
I just use normal wires or pieces clipped from components.
The caps are russian military grade stuff. 400 volt types.Btw, what's an "LPV Russian"???