Tony, I did have a look on your website and see there's a totally different finish on most of these in the pics. The standard original smooth casting surface as it should be.
For certain these carbs had a history in someone's sandblasting cabinet then. It's good to know the procedure you have and takes away the doubt of quality.
I have seen too much from so called experts in the classic car world and also people destroying alloy parts and carbs with grit blasting and seeing these I had my doubts. When someone even starts blasting these with grit shows they don't even understand anything of carbs. Everybody can put shiny screws and linkages on a carb and sells as overhauled, and a lot do, having the tolerances a lot worse as before the overhaul. I even have seen carbs with the old throttlevalves zinc plated and fitted again..
Reading you comment's I think these are fine to fit.
The finish you see in the photos are somewhat misleading, I don't know if it's lighting, shadows etc, because the alloy finish on the carbs are perfect.
As far as "For certain these carbs had a history in someone's sandblasting cabinet then", is nonsense
, they're lovely - just how they left Tony's.
But, I'm glad you've given your approval ("I think these are fine to fit."), I can rest easy now....