Life is just not simple. Here are just a couple potential "poor fit" issues we noticed, - even when using genuine Weinmann made hoods:

Hood shown at the top will not wrap properly around the square body of the alloy lever.




Notice how the edge of the hood opening does not seat correctly around this lever.




This black hood would fit on the square edge of this lever body... BUT, the hood's "stack" is too tall for the adjuster shaft to exit properly out the top.
The threaded shaft might fit and then end flush with the top of the hood, but the plastic adjuster would not thread on... and that part is required on this lever because it serves as the cable housing stop. A possible remedy here might be to literally slice off some of the top the hood, but this would leave a wide unattractive stump at the top edge, so this would really only be a last resort modification.