It is a club aluminium dutch oven from the 50's. It is discolored on the interior and has baked on dirt on the exterior. The exterior has a textured surface which makes cleaning more difficult. I tried baking soda and water paste, but it did not budge it!
Even though it's a keepsake, you might think of switching to stainless steel. It's questionable whether the aluminum is healthy since elements of the metal may taint your food and get into your body.
I have an aluminum double boiler.. that I only used for making pie pudding and yes, it got yucky. I found something and I cleaned it and i was so proud of myself but that was a while ago and it am racking my brain to remember. If I recall, I'll try to get back to you and let you know, but for now, I think it was the using CLR cleaner. Good luck. And if they say not to use it... I'd say it was time to update. Clean it... for display or sale to collectors.
Aluminum in that form for cooking really isn't safe anymore. Use it for a planter. The only really safe Aluminum cookware is Anodized (hardened on the outside). They have found that with he softer forms of Aluminum you are actually getting it in your food - they think this could be a link to Alzheimer's Disease.
