LocostUSA.com

Basically none of the 'Net suggestions for home brew aluminum cleaners really work for castings that have water stain/black spots damage.
Vinegar is no better than plain water.
A nylon brush may remove dirt and soft crud but has No effect on stains.
Cream of Tartar & Vinegar paste is a waste, save it for baking.
A brass brush is somewhat effective but changes the appearance to a soft polish without actually removing any but the lightest stains.
So this set of Dellorto's will be getting soda blasted.
I've done this before and it really cleans the aluminum but Still will not remove heavy stains.
Glass Bead blasting will take out stains but is too aggressive at close range and disappointing from a distance.
I will probably end up painting the major pieces for the best finish as Vapor/Dry Ice blasting is just not available to me.

_________________
If I must be a one-man PC free zone, so be it!

Walnut shells for blasting media?
This eliminates the dull sand blasted appearance and gives a new almost polished look.
Although the idea of blasting a carb body violates all carb cleaning directives.
You would have to pay special attention to manually cleaning each passage afterwards.
Masking might be effective.

_________________
Honey anyone?

Have you tried mag wheel cleaner? I have had very good results
Another cleaner is concentrate that is used to clean aluminum semi trailers. Got to be careful with this as too much acid to water will start pitting the aluminum.

I recall trying walnut shells before and being disappointed they were not more effective.
Once they are completely stripped I will be very careful with the blast gun.
Soda is good here as it dissolves in water.
I am considering painting this set so a soda blast finish would be fine.
Cannot seem to locate Aluminum Jelly anymore, EPA?

_________________
If I must be a one-man PC free zone, so be it!

Loctite makes some, available on Amazon (8 oz). Have not used it. Last time I did carbs, I used the 5 gal bucket of carb cleaner.
If you keep it long enough, it will eat through the metal bucket.