Parts are available just not Chinese parts, buy Stihl OEM.
You have to 'submerge' the entire part in Argon before welding in a metal tank and Lathanated Tungsten is the electrode by the way if it's Magnesium. If it's die cast aluminum, you can use straight Tungsten and 100% argon shielding gas. I always use a water cooled torch with superflex hoses. None of that stuff is cheap today from the TIG machine to the water cooled torch to the water cooler itself but we do certified welting here as well as custom machining and CNC plasma cutting and everything today is expensive and getting worse, why small outfits like mine are folding up, cannot afford to stay in business and customer like to take their good old time paying too. Hell, I took 4 increases in steel, aluminum and stainless cost this year not to mention consumables cost. Even my utilities went up and our insurance for the shop and farm jumped 30% as well. Getting harder to eat and keep the shop running and pay my 2 employees. Thank the load, most everything is paid off and what isn't I pay no interest or finance charges on either. In fact, if cannot get deferred interest or finance charges waived, I don't buy it. I keep the older stuff that is paid for unless I can sell the old stuff and at least break even. Just bought a new TIG welder and 2 plasma cutters, one for the CNC plasma table and one for the shop to hand cut stuff. Sold my old Lincoln Square Wave TIG weld pak machine and my HT 89 amp plasma cutter to a guy up town (that has money and wanted them and I gouged him too. I went away and bought 2 new machines a a new refillable 120 Cu.ft. bottle of 100% argon and put 2 grand in my pocket. The Lincoln was old technology and the HT was as well plus the HT consumables have gotten priced out of sight, so they are gone and forgotten about. My new machines are all IGBT inverter machines, no heavy transformers and all 100% digital readout with memory inside and the cost was a lot less too and IGBT machines are much more efficient on energy consumption as well. Things like food and hard goods are only going to get worse.