It shouldn’t be 3/4″ by 1/8″ strip anyway….
It should be 5/8″ by 1/8″ on vintage Flying Squirrels, TT Replicas, and Sprint Specials. ( I have encountered 3/4″ by 1/8″ stays on ‘works’ bikes. and SOME TT Reps) The really correct stuff has rounded edges, not sharp 90 degrees, and it is not BMS (Bright Mild Steel), but Rolled Strip. The right stuff carries black “Mill Scale” when bought new. If it is getting hard to find in our ruddy metric age I had better try and find some and put it ‘in stock’ !! However 16mm x 3mm or 3.5mm is unlikely to be noticed, especially when layers of primer, undercoat, and gloss paint are added !