My experience with SUs was over 50 years ago with carbs that were less than 10 years old at the time. Your carbs are over 45 years old so likely have a fair bit more wear and tear inside the damping cylinders even with new seals. Problem for me with something like this is if you don't make a habit of checking it at some kind of regular interval then you start forgetting to check it when you're busy. Good luck and hope you get to keep enjoying that old family car of yours for many years to come.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now