lol well I have these old fussy cake recipes that say, add a tablespoon of milk and if you already have 3 eggs in...you're up by a tablespoon of egg already.
I have a US set of wet and dry cups, a Canadian set of dry cups (10% more!) and a scale for Euro stuff. If I have an old recipe and I want it to fit in my pan/bottle, I make sure to use the US set. Modern recipes local made with big eggs and 500g pounds and 250 ml cups, I use the Canadian set. My generous sized set. Then you keep the right ratio of wet:dry: fat.