My $40 harbor freight anvil stand wobble took 3 weekends to fix

Picked up a cast iron stand for my 70 lb anvil back in April and the thing wobbled like a rocking chair no matter how I set it. Tightened the bolts, added shims under the feet, even bolted it to a 2x6 base and it still moved sideways when I hammered. Turned out the mounting plate on the anvil itself was slightly convex from the factory, so only the middle touched the stand. I spent two full weekends grinding the bottom flat with an angle grinder and checking with a straightedge, then another weekend filling the gap with JB Weld and sand. Finally got it stable last Tuesday and now it barely shifts even on heavy draws. Anyone else ever find their anvil base is warped straight from the store, or did I just get the one bad casting in the batch?