If they where 48s I would have bought them at that price
the copycats have no idea how sought after 45/48s are and
how more common original 40s are yet take same amount of
materials to make them a tad bigger.

The casting is fine and better than the Spanish ones
Its just an option to new webers and often worn SH ones

All carbs need rejetting unless engine are exactly the
same in everyway which is rare.