Good to see that you have the reinforcements welded in - I would hate to have been the one to break the bad news to you
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Regarding the oil in the Konis - yes, it's there to help cool the insert by conducting the heat from the insert to the outer strut housing. The Konis in my '77 had the oil in there as well. I forget the amount (50ml?), but if you search you can find how much should be in there when you go to re-assemble.