Combine hamburger, onion, salt and oatmeal. Add milk as needed for hamburger mixture to hold shape. Make 3/4 - 1 inch meatballs with all of mixture. Place in oven safe casserole dish (I use throw away pans because the BBQ sauce can be hard to get off.).
Sauce:
Mix vinegar, sugar, water, ketchup and Worcestershire sauce.
Pour mixture over meatballs.
Bake in oven at 375°F for 15 - 20 minutes. Reduce heat to 350°F for 70 - 75 minutes.
Start cooking egg noodles about 30 minutes before meatballs are done. Serve meatballs over noodles.