I also had several sets of adjustables, with the cut (1800) tab, and no flaking, rust or nothing (and I didn't coat the cut surface at all).
But I have to say, the Kuryakyn Wide Chrome (non-adjustables) made for 1500 levers (#7429) are a shorter reach and much more comfortable than OE. Probably as short a reach as the adjustables on 3 or even 2 (of 5) on the adjustables, and more sturdy without the adjustable mechanism. I have girl size hands, and the Kury's are perfect for me, and no cutting a tab necessary.
There was another issue with the 1800 adjustables (with cut tab, on the clutch side), and that was the hand brake lever was causing the brake light to stay on for 1-3 seconds after I released the lever. This had to do with the mate-up of that lever with the brake light switch, and took quite a bit of fooling around and a little cleaning and filing to clear up. I would have never known of this problem, until the guy behind me in a group ride complained about me staying on the brakes too long through the twisties.
Here is a Delphi link to the adjustable levers, and the brake light issue at the bottom.
http://forums.delphiforums.com/valkyrie/messages/?msg=13360.1 https://www.denniskirk.com/kuryakyn/wide-style-levers-7429.p572164.prd/572164.sku